Merge remote-tracking branch 'origin/develop' into feature/struct_property_rewrite.feature/struct_property_rewrite

389 files changed, 3337 insertions, 1927 deletions

diff --git a/SmartDeviceLink-iOS.xcodeproj/project.pbxproj b/SmartDeviceLink-iOS.xcodeproj/project.pbxproj
index 2d4d72077..3bb5759c9 100644
--- a/SmartDeviceLink-iOS.xcodeproj/project.pbxproj
+++ b/SmartDeviceLink-iOS.xcodeproj/project.pbxproj
@@ -359,7 +359,6 @@
 		5D61FC6E1A84238C00846EE7 /* SDLCreateInteractionChoiceSetResponse.m in Sources */ = {isa = PBXBuildFile; fileRef = 5D61FA811A84238A00846EE7 /* SDLCreateInteractionChoiceSetResponse.m */; };
 		5D61FC6F1A84238C00846EE7 /* SDLDebugTool.h in Headers */ = {isa = PBXBuildFile; fileRef = 5D61FA821A84238A00846EE7 /* SDLDebugTool.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		5D61FC701A84238C00846EE7 /* SDLDebugTool.m in Sources */ = {isa = PBXBuildFile; fileRef = 5D61FA831A84238A00846EE7 /* SDLDebugTool.m */; };
-		5D61FC711A84238C00846EE7 /* SDLDecoder.h in Headers */ = {isa = PBXBuildFile; fileRef = 5D61FA841A84238A00846EE7 /* SDLDecoder.h */; };
 		5D61FC721A84238C00846EE7 /* SDLDeleteCommand.h in Headers */ = {isa = PBXBuildFile; fileRef = 5D61FA851A84238A00846EE7 /* SDLDeleteCommand.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		5D61FC731A84238C00846EE7 /* SDLDeleteCommand.m in Sources */ = {isa = PBXBuildFile; fileRef = 5D61FA861A84238A00846EE7 /* SDLDeleteCommand.m */; };
 		5D61FC741A84238C00846EE7 /* SDLDeleteCommandResponse.h in Headers */ = {isa = PBXBuildFile; fileRef = 5D61FA871A84238A00846EE7 /* SDLDeleteCommandResponse.h */; settings = {ATTRIBUTES = (Public, ); }; };
@@ -408,7 +407,6 @@
 		5D61FC9F1A84238C00846EE7 /* SDLEncodedSyncPData.m in Sources */ = {isa = PBXBuildFile; fileRef = 5D61FAB21A84238A00846EE7 /* SDLEncodedSyncPData.m */; };
 		5D61FCA01A84238C00846EE7 /* SDLEncodedSyncPDataResponse.h in Headers */ = {isa = PBXBuildFile; fileRef = 5D61FAB31A84238A00846EE7 /* SDLEncodedSyncPDataResponse.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		5D61FCA11A84238C00846EE7 /* SDLEncodedSyncPDataResponse.m in Sources */ = {isa = PBXBuildFile; fileRef = 5D61FAB41A84238A00846EE7 /* SDLEncodedSyncPDataResponse.m */; };
-		5D61FCA21A84238C00846EE7 /* SDLEncoder.h in Headers */ = {isa = PBXBuildFile; fileRef = 5D61FAB51A84238A00846EE7 /* SDLEncoder.h */; };
 		5D61FCA31A84238C00846EE7 /* SDLEndAudioPassThru.h in Headers */ = {isa = PBXBuildFile; fileRef = 5D61FAB61A84238A00846EE7 /* SDLEndAudioPassThru.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		5D61FCA41A84238C00846EE7 /* SDLEndAudioPassThru.m in Sources */ = {isa = PBXBuildFile; fileRef = 5D61FAB71A84238A00846EE7 /* SDLEndAudioPassThru.m */; };
 		5D61FCA51A84238C00846EE7 /* SDLEndAudioPassThruResponse.h in Headers */ = {isa = PBXBuildFile; fileRef = 5D61FAB81A84238A00846EE7 /* SDLEndAudioPassThruResponse.h */; settings = {ATTRIBUTES = (Public, ); }; };
@@ -1390,7 +1388,6 @@
 		5D61FA811A84238A00846EE7 /* SDLCreateInteractionChoiceSetResponse.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = SDLCreateInteractionChoiceSetResponse.m; sourceTree = "<group>"; };
 		5D61FA821A84238A00846EE7 /* SDLDebugTool.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = SDLDebugTool.h; sourceTree = "<group>"; };
 		5D61FA831A84238A00846EE7 /* SDLDebugTool.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = SDLDebugTool.m; sourceTree = "<group>"; };
-		5D61FA841A84238A00846EE7 /* SDLDecoder.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = SDLDecoder.h; sourceTree = "<group>"; };
 		5D61FA851A84238A00846EE7 /* SDLDeleteCommand.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = SDLDeleteCommand.h; sourceTree = "<group>"; };
 		5D61FA861A84238A00846EE7 /* SDLDeleteCommand.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = SDLDeleteCommand.m; sourceTree = "<group>"; };
 		5D61FA871A84238A00846EE7 /* SDLDeleteCommandResponse.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = SDLDeleteCommandResponse.h; sourceTree = "<group>"; };
@@ -1439,7 +1436,6 @@
 		5D61FAB21A84238A00846EE7 /* SDLEncodedSyncPData.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = SDLEncodedSyncPData.m; sourceTree = "<group>"; };
 		5D61FAB31A84238A00846EE7 /* SDLEncodedSyncPDataResponse.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = SDLEncodedSyncPDataResponse.h; sourceTree = "<group>"; };
 		5D61FAB41A84238A00846EE7 /* SDLEncodedSyncPDataResponse.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = SDLEncodedSyncPDataResponse.m; sourceTree = "<group>"; };
-		5D61FAB51A84238A00846EE7 /* SDLEncoder.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = SDLEncoder.h; sourceTree = "<group>"; };
 		5D61FAB61A84238A00846EE7 /* SDLEndAudioPassThru.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = SDLEndAudioPassThru.h; sourceTree = "<group>"; };
 		5D61FAB71A84238A00846EE7 /* SDLEndAudioPassThru.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = SDLEndAudioPassThru.m; sourceTree = "<group>"; };
 		5D61FAB81A84238A00846EE7 /* SDLEndAudioPassThruResponse.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = SDLEndAudioPassThruResponse.h; sourceTree = "<group>"; };
@@ -1493,10 +1489,6 @@
 		5D61FAE91A84238A00846EE7 /* SDLImageType.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = SDLImageType.m; sourceTree = "<group>"; };
 		5D61FAEA1A84238A00846EE7 /* SDLInteractionMode.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = SDLInteractionMode.h; sourceTree = "<group>"; };
 		5D61FAEB1A84238A00846EE7 /* SDLInteractionMode.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = SDLInteractionMode.m; sourceTree = "<group>"; };
-		5D61FAEF1A84238A00846EE7 /* SDLJsonDecoder.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = SDLJsonDecoder.h; sourceTree = "<group>"; };
-		5D61FAF01A84238A00846EE7 /* SDLJsonDecoder.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = SDLJsonDecoder.m; sourceTree = "<group>"; };
-		5D61FAF11A84238A00846EE7 /* SDLJsonEncoder.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = SDLJsonEncoder.h; sourceTree = "<group>"; };
-		5D61FAF21A84238A00846EE7 /* SDLJsonEncoder.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = SDLJsonEncoder.m; sourceTree = "<group>"; };
 		5D61FAF31A84238A00846EE7 /* SDLKeyboardEvent.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = SDLKeyboardEvent.h; sourceTree = "<group>"; };
 		5D61FAF41A84238A00846EE7 /* SDLKeyboardEvent.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = SDLKeyboardEvent.m; sourceTree = "<group>"; };
 		5D61FAF51A84238A00846EE7 /* SDLKeyboardLayout.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = SDLKeyboardLayout.h; sourceTree = "<group>"; };
@@ -2655,6 +2647,8 @@
 				5D61FB771A84238B00846EE7 /* SDLResetGlobalProperties.m */,
 				5D61FB8E1A84238B00846EE7 /* SDLScrollableMessage.h */,
 				5D61FB8F1A84238B00846EE7 /* SDLScrollableMessage.m */,
+				5DCF76F31ACDBAD300BB647B /* SDLSendLocation.h */,
+				5DCF76F41ACDBAD300BB647B /* SDLSendLocation.m */,
 				5D61FB921A84238B00846EE7 /* SDLSetAppIcon.h */,
 				5D61FB931A84238B00846EE7 /* SDLSetAppIcon.m */,
 				5D61FB961A84238B00846EE7 /* SDLSetDisplayLayout.h */,
@@ -2691,8 +2685,6 @@
 				DA9F7E921DCC04E400ACAE48 /* SDLUnsubscribeWaypoints.m */,
 				5D61FC041A84238C00846EE7 /* SDLUpdateTurnList.h */,
 				5D61FC051A84238C00846EE7 /* SDLUpdateTurnList.m */,
-				5DCF76F31ACDBAD300BB647B /* SDLSendLocation.h */,
-				5DCF76F41ACDBAD300BB647B /* SDLSendLocation.m */,
 			);
 			name = Requests;
 			sourceTree = "<group>";
@@ -2752,6 +2744,8 @@
 				5D61FB791A84238B00846EE7 /* SDLResetGlobalPropertiesResponse.m */,
 				5D61FB901A84238B00846EE7 /* SDLScrollableMessageResponse.h */,
 				5D61FB911A84238B00846EE7 /* SDLScrollableMessageResponse.m */,
+				5DCF76F71ACDD7CD00BB647B /* SDLSendLocationResponse.h */,
+				5DCF76F81ACDD7CD00BB647B /* SDLSendLocationResponse.m */,
 				5D61FB941A84238B00846EE7 /* SDLSetAppIconResponse.h */,
 				5D61FB951A84238B00846EE7 /* SDLSetAppIconResponse.m */,
 				5D61FB981A84238B00846EE7 /* SDLSetDisplayLayoutResponse.h */,
@@ -2788,8 +2782,6 @@
 				DA9F7E8E1DCC04C000ACAE48 /* SDLUnsubscribeWaypointsResponse.m */,
 				5D61FC061A84238C00846EE7 /* SDLUpdateTurnListResponse.h */,
 				5D61FC071A84238C00846EE7 /* SDLUpdateTurnListResponse.m */,
-				5DCF76F71ACDD7CD00BB647B /* SDLSendLocationResponse.h */,
-				5DCF76F81ACDD7CD00BB647B /* SDLSendLocationResponse.m */,
 			);
 			name = Responses;
 			sourceTree = "<group>";
@@ -3059,7 +3051,6 @@
 				DAC5724C1D0FE3B60004288B /* Touches */,
 				5DCC199D1B8221D2004FFAD9 /* HTTP Connection */,
 				E9C32B831AB20B2900F283AF /* @categories */,
-				5D5934F71A8519A700687FB9 /* JSON */,
 				5D5934F91A851A8000687FB9 /* Prioritized Objects */,
 				5D61FAD21A84238A00846EE7 /* SDLHexUtility.h */,
 				5D61FAD31A84238A00846EE7 /* SDLHexUtility.m */,
@@ -3074,18 +3065,6 @@
 			name = Utilities;
 			sourceTree = "<group>";
 		};
-		5D5934F71A8519A700687FB9 /* JSON */ = {
-			isa = PBXGroup;
-			children = (
-				5D5934FD1A851B1500687FB9 /* @protocols */,
-				5D61FAEF1A84238A00846EE7 /* SDLJsonDecoder.h */,
-				5D61FAF01A84238A00846EE7 /* SDLJsonDecoder.m */,
-				5D61FAF11A84238A00846EE7 /* SDLJsonEncoder.h */,
-				5D61FAF21A84238A00846EE7 /* SDLJsonEncoder.m */,
-			);
-			name = JSON;
-			sourceTree = "<group>";
-		};
 		5D5934F81A8519C300687FB9 /* Notification */ = {
 			isa = PBXGroup;
 			children = (
@@ -3150,15 +3129,6 @@
 			name = "@protocols";
 			sourceTree = "<group>";
 		};
-		5D5934FD1A851B1500687FB9 /* @protocols */ = {
-			isa = PBXGroup;
-			children = (
-				5D61FA841A84238A00846EE7 /* SDLDecoder.h */,
-				5D61FAB51A84238A00846EE7 /* SDLEncoder.h */,
-			);
-			name = "@protocols";
-			sourceTree = "<group>";
-		};
 		5D5934FE1A851B2500687FB9 /* @protocols */ = {
 			isa = PBXGroup;
 			children = (
@@ -4164,8 +4134,6 @@
 				DAC5726C1D11B4840004288B /* SDLTouchManagerDelegate.h in Headers */,
 				5D61FD3F1A84238C00846EE7 /* SDLPrioritizedObjectCollection.h in Headers */,
 				5D61FCBF1A84238C00846EE7 /* SDLHexUtility.h in Headers */,
-				5D61FCA21A84238C00846EE7 /* SDLEncoder.h in Headers */,
-				5D61FC711A84238C00846EE7 /* SDLDecoder.h in Headers */,
 				5D61FD6F1A84238C00846EE7 /* SDLRPCPayload.h in Headers */,
 				5D61FCF01A84238C00846EE7 /* SDLLockScreenStatusManager.h in Headers */,
 				5D61FD311A84238C00846EE7 /* SDLPolicyDataParser.h in Headers */,
@@ -4244,6 +4212,7 @@
 				TargetAttributes = {
 					5D4019AE1A76EC350006B0C2 = {
 						CreatedOnToolsVersion = 6.1.1;
+						DevelopmentTeam = ACNGAAM3M7;
 						SystemCapabilities = {
 							com.apple.BackgroundModes = {
 								enabled = 1;
@@ -5109,6 +5078,7 @@
 			buildSettings = {
 				ASSETCATALOG_COMPILER_APPICON_NAME = AppIcon;
 				CODE_SIGN_IDENTITY = "iPhone Developer";
+				DEVELOPMENT_TEAM = ACNGAAM3M7;
 				INFOPLIST_FILE = "$(SRCROOT)/SmartDeviceLink_Example/Info.plist";
 				IPHONEOS_DEPLOYMENT_TARGET = 8.0;
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks";
@@ -5122,6 +5092,7 @@
 			buildSettings = {
 				ASSETCATALOG_COMPILER_APPICON_NAME = AppIcon;
 				CODE_SIGN_IDENTITY = "iPhone Developer";
+				DEVELOPMENT_TEAM = ACNGAAM3M7;
 				INFOPLIST_FILE = "$(SRCROOT)/SmartDeviceLink_Example/Info.plist";
 				IPHONEOS_DEPLOYMENT_TARGET = 8.0;
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks";
diff --git a/SmartDeviceLink/EAAccessory+SDLProtocols.h b/SmartDeviceLink/EAAccessory+SDLProtocols.h
index 417b5b07b..0c729b796 100644
--- a/SmartDeviceLink/EAAccessory+SDLProtocols.h
+++ b/SmartDeviceLink/EAAccessory+SDLProtocols.h
@@ -4,8 +4,12 @@
 
 #import <ExternalAccessory/ExternalAccessory.h>
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface EAAccessory (SDLProtocols)
 
 - (BOOL)supportsProtocol:(NSString *)protocol;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/EAAccessory+SDLProtocols.m b/SmartDeviceLink/EAAccessory+SDLProtocols.m
index bffeeb829..881fea352 100644
--- a/SmartDeviceLink/EAAccessory+SDLProtocols.m
+++ b/SmartDeviceLink/EAAccessory+SDLProtocols.m
@@ -4,6 +4,8 @@
 
 #import "EAAccessory+SDLProtocols.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation EAAccessory (SDLProtocols)
 
 - (BOOL)supportsProtocol:(NSString *)protocol {
@@ -17,3 +19,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/EAAccessoryManager+SDLProtocols.h b/SmartDeviceLink/EAAccessoryManager+SDLProtocols.h
index b4b39d943..c2d45cb2e 100644
--- a/SmartDeviceLink/EAAccessoryManager+SDLProtocols.h
+++ b/SmartDeviceLink/EAAccessoryManager+SDLProtocols.h
@@ -4,8 +4,12 @@
 
 #import <ExternalAccessory/ExternalAccessory.h>
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface EAAccessoryManager (SDLProtocols)
 
-+ (EAAccessory *)findAccessoryForProtocol:(NSString *)protocol;
++ (nullable EAAccessory *)findAccessoryForProtocol:(NSString *)protocol;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/EAAccessoryManager+SDLProtocols.m b/SmartDeviceLink/EAAccessoryManager+SDLProtocols.m
index 38b0b2477..69d5f408a 100644
--- a/SmartDeviceLink/EAAccessoryManager+SDLProtocols.m
+++ b/SmartDeviceLink/EAAccessoryManager+SDLProtocols.m
@@ -5,9 +5,11 @@
 #import "EAAccessory+SDLProtocols.h"
 #import "EAAccessoryManager+SDLProtocols.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation EAAccessoryManager (SDLProtocols)
 
-+ (EAAccessory *)findAccessoryForProtocol:(NSString *)protocol {
++ (nullable EAAccessory *)findAccessoryForProtocol:(NSString *)protocol {
     for (EAAccessory *accessory in [[EAAccessoryManager sharedAccessoryManager] connectedAccessories]) {
         if ([accessory supportsProtocol:protocol]) {
             return accessory;
@@ -18,3 +20,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/NSThread+ThreadIndex.h b/SmartDeviceLink/NSThread+ThreadIndex.h
index 60459e3e2..19bf1204d 100644
--- a/SmartDeviceLink/NSThread+ThreadIndex.h
+++ b/SmartDeviceLink/NSThread+ThreadIndex.h
@@ -4,6 +4,10 @@
 
 #import <Foundation/Foundation.h>
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface NSThread (ThreadIndex)
 - (NSInteger)threadIndex;
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/NSThread+ThreadIndex.m b/SmartDeviceLink/NSThread+ThreadIndex.m
index 88d58c9f3..6238359fe 100644
--- a/SmartDeviceLink/NSThread+ThreadIndex.m
+++ b/SmartDeviceLink/NSThread+ThreadIndex.m
@@ -4,6 +4,8 @@
 
 #import "NSThread+ThreadIndex.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation NSThread (ThreadIndex)
 
 - (NSInteger)threadIndex {
@@ -21,3 +23,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLAbstractProtocol.h b/SmartDeviceLink/SDLAbstractProtocol.h
index ee9e8a79e..45e00b434 100644
--- a/SmartDeviceLink/SDLAbstractProtocol.h
+++ b/SmartDeviceLink/SDLAbstractProtocol.h
@@ -9,13 +9,14 @@
 #import "SDLSecurityType.h"
 #import "SDLTransportDelegate.h"
 
+NS_ASSUME_NONNULL_BEGIN
 
 @interface SDLAbstractProtocol : NSObject <SDLTransportDelegate>
 
-@property (strong) NSString *debugConsoleGroupName;
-@property (weak) SDLAbstractTransport *transport;
-@property (strong) NSHashTable<id<SDLProtocolListener>> *protocolDelegateTable;
-@property (nonatomic, strong) id<SDLSecurityType> securityManager;
+@property (strong, nonatomic) NSString *debugConsoleGroupName;
+@property (nullable, weak, nonatomic) SDLAbstractTransport *transport;
+@property (nullable, strong, nonatomic) NSHashTable<id<SDLProtocolListener>> *protocolDelegateTable;
+@property (nullable, nonatomic, strong) id<SDLSecurityType> securityManager;
 @property (nonatomic, copy) NSString *appId;
 
 // Sending
@@ -35,6 +36,7 @@
 
 // Recieving
 - (void)handleBytesFromTransport:(NSData *)receivedData;
-- (void)dispose;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLAbstractProtocol.m b/SmartDeviceLink/SDLAbstractProtocol.m
index 37d18bfef..09b882b66 100644
--- a/SmartDeviceLink/SDLAbstractProtocol.m
+++ b/SmartDeviceLink/SDLAbstractProtocol.m
@@ -4,6 +4,7 @@
 
 #import "SDLRPCMessage.h"
 
+NS_ASSUME_NONNULL_BEGIN
 
 @implementation SDLAbstractProtocol
 
@@ -69,10 +70,6 @@
     [self doesNotRecognizeSelector:_cmd];
 }
 
-- (void)dispose {
-    [self doesNotRecognizeSelector:_cmd];
-}
-
 
 #pragma - SDLTransportListener Implementation
 - (void)onTransportConnected {
@@ -96,3 +93,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLAbstractTransport.h b/SmartDeviceLink/SDLAbstractTransport.h
index a8a1f61be..0273b8425 100644
--- a/SmartDeviceLink/SDLAbstractTransport.h
+++ b/SmartDeviceLink/SDLAbstractTransport.h
@@ -4,15 +4,18 @@
 
 #import "SDLTransportDelegate.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLAbstractTransport : NSObject
 
-@property (weak) id<SDLTransportDelegate> delegate;
-@property (strong) NSString *debugConsoleGroupName;
+@property (nullable, weak, nonatomic) id<SDLTransportDelegate> delegate;
+@property (strong, nonatomic) NSString *debugConsoleGroupName;
 
 - (void)connect;
 - (void)disconnect;
 - (void)sendData:(NSData *)dataToSend;
-- (void)dispose;
 - (double)retryDelay;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLAbstractTransport.m b/SmartDeviceLink/SDLAbstractTransport.m
index 6d7437748..4f2657bd2 100644
--- a/SmartDeviceLink/SDLAbstractTransport.m
+++ b/SmartDeviceLink/SDLAbstractTransport.m
@@ -2,6 +2,8 @@
 
 #import "SDLAbstractTransport.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLAbstractTransport
 
 - (instancetype)init {
@@ -22,13 +24,11 @@
     [self doesNotRecognizeSelector:_cmd];
 }
 
-- (void)dispose {
-    [self doesNotRecognizeSelector:_cmd];
-}
-
 - (double)retryDelay {
     [self doesNotRecognizeSelector:_cmd];
     return 0.0;
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLAddCommand.h b/SmartDeviceLink/SDLAddCommand.h
index 4060f2fe2..59ef5cb02 100644
--- a/SmartDeviceLink/SDLAddCommand.h
+++ b/SmartDeviceLink/SDLAddCommand.h
@@ -34,6 +34,9 @@
  *
  * @see SDLDeleteCommand SDLAddSubMenu SDLDeleteSubMenu
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLAddCommand : SDLRPCRequest <SDLRequestHandler>
 
 /**
@@ -43,20 +46,20 @@
  *
  *  @return An SDLAddCommand object
  */
-- (instancetype)initWithHandler:(SDLRPCNotificationHandler)handler;
+- (instancetype)initWithHandler:(nullable SDLRPCNotificationHandler)handler;
 
-- (instancetype)initWithId:(UInt32)commandId vrCommands:(NSArray<NSString *> *)vrCommands handler:(SDLRPCNotificationHandler)handler;
+- (instancetype)initWithId:(UInt32)commandId vrCommands:(nullable NSArray<NSString *> *)vrCommands handler:(nullable SDLRPCNotificationHandler)handler;
 
-- (instancetype)initWithId:(UInt32)commandId vrCommands:(NSArray<NSString *> *)vrCommands menuName:(NSString *)menuName handler:(SDLRPCNotificationHandler)handler;
+- (instancetype)initWithId:(UInt32)commandId vrCommands:(nullable NSArray<NSString *> *)vrCommands menuName:(NSString *)menuName handler:(SDLRPCNotificationHandler)handler;
 
-- (instancetype)initWithId:(UInt32)commandId vrCommands:(NSArray<NSString *> *)vrCommands menuName:(NSString *)menuName parentId:(UInt32)parentId position:(UInt16)position iconValue:(NSString *)iconValue iconType:(SDLImageType)iconType handler:(SDLRPCNotificationHandler)handler;
+- (instancetype)initWithId:(UInt32)commandId vrCommands:(nullable NSArray<NSString *> *)vrCommands menuName:(NSString *)menuName parentId:(UInt32)parentId position:(UInt16)position iconValue:(NSString *)iconValue iconType:(SDLImageType)iconType handler:(nullable SDLRPCNotificationHandler)handler;
 
 /**
  *  A handler that will let you know when the button you created is subscribed.
  *
  *  @warning This will only work if you use SDLManager.
  */
-@property (copy, nonatomic) SDLRPCNotificationHandler handler;
+@property (nullable, copy, nonatomic) SDLRPCNotificationHandler handler;
 
 /**
  * @abstract A Unique Command ID that identifies the command
@@ -65,7 +68,7 @@
  *
  * Required, Integer, 0 - 2,000,000,000
  */
-@property (strong) NSNumber<SDLInt> *cmdID;
+@property (strong, nonatomic) NSNumber<SDLInt> *cmdID;
 
 /**
  * @abstract a *SDLMenuParams* pointer which will defined the command and how it is added to the Command Menu
@@ -77,7 +80,7 @@
  *
  * Optional
  */
-@property (strong) SDLMenuParams *menuParams;
+@property (nullable, strong, nonatomic) SDLMenuParams *menuParams;
 
 /**
  * @abstract An array of strings to be used as VR synonyms for this command.
@@ -88,7 +91,7 @@
  *
  * Optional, Array of Strings, Max String length 99 chars, Array size 1 - 100
  */
-@property (strong) NSMutableArray<NSString *> *vrCommands;
+@property (nullable, strong, nonatomic) NSMutableArray<NSString *> *vrCommands;
 
 /**
  * @abstract Image struct containing a static or dynamic icon
@@ -99,6 +102,8 @@
  *
  * Optional
  */
-@property (strong) SDLImage *cmdIcon;
+@property (nullable, strong, nonatomic) SDLImage *cmdIcon;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLAddCommand.m b/SmartDeviceLink/SDLAddCommand.m
index 454e41815..ddf4ee4ce 100644
--- a/SmartDeviceLink/SDLAddCommand.m
+++ b/SmartDeviceLink/SDLAddCommand.m
@@ -9,6 +9,8 @@
 #import "SDLMenuParams.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLAddCommand
 
 - (instancetype)init {
@@ -17,7 +19,7 @@
     return self;
 }
 
-- (instancetype)initWithHandler:(SDLRPCNotificationHandler)handler {
+- (instancetype)initWithHandler:(nullable SDLRPCNotificationHandler)handler {
     self = [self init];
     if (!self) {
         return nil;
@@ -28,29 +30,31 @@
     return self;
 }
 
-- (instancetype)initWithId:(UInt32)commandId vrCommands:(NSArray<NSString *> *)vrCommands handler:(SDLRPCNotificationHandler)handler {
-    return [self initWithId:commandId vrCommands:vrCommands menuName:nil handler:handler];
-}
-
-- (instancetype)initWithId:(UInt32)commandId vrCommands:(NSArray<NSString *> *)vrCommands menuName:(NSString *)menuName handler:(SDLRPCNotificationHandler)handler {
+- (instancetype)initWithId:(UInt32)commandId vrCommands:(nullable NSArray<NSString *> *)vrCommands handler:(nullable SDLRPCNotificationHandler)handler {
     self = [self init];
     if (!self) {
         return nil;
     }
-
+    
     self.cmdID = @(commandId);
-
-    if (menuName != nil) {
-        self.menuParams = [[SDLMenuParams alloc] initWithMenuName:menuName];
-    }
-
     self.vrCommands = [vrCommands mutableCopy];
     self.handler = handler;
+    
+    return self;
+}
 
+- (instancetype)initWithId:(UInt32)commandId vrCommands:(nullable NSArray<NSString *> *)vrCommands menuName:(NSString *)menuName handler:(SDLRPCNotificationHandler)handler {
+    self = [self initWithId:commandId vrCommands:vrCommands handler:handler];
+    if (!self) {
+        return nil;
+    }
+    
+    self.menuParams = [[SDLMenuParams alloc] initWithMenuName:menuName];
+    
     return self;
 }
 
-- (instancetype)initWithId:(UInt32)commandId vrCommands:(NSArray<NSString *> *)vrCommands menuName:(NSString *)menuName parentId:(UInt32)parentId position:(UInt16)position iconValue:(NSString *)iconValue iconType:(SDLImageType)iconType handler:(SDLRPCNotificationHandler)handler {
+- (instancetype)initWithId:(UInt32)commandId vrCommands:(nullable NSArray<NSString *> *)vrCommands menuName:(NSString *)menuName parentId:(UInt32)parentId position:(UInt16)position iconValue:(NSString *)iconValue iconType:(SDLImageType)iconType handler:(nullable SDLRPCNotificationHandler)handler {
     self = [self initWithId:commandId vrCommands:vrCommands menuName:menuName handler:handler];
     if (!self) {
         return nil;
@@ -59,9 +63,7 @@
     self.menuParams.parentID = @(parentId);
     self.menuParams.position = @(position);
 
-    if (iconValue != nil && iconType != nil) {
-        self.cmdIcon = [[SDLImage alloc] initWithName:iconValue ofType:iconType];
-    }
+    self.cmdIcon = [[SDLImage alloc] initWithName:iconValue ofType:iconType];
 
     return self;
 }
@@ -74,28 +76,30 @@
     return [parameters sdl_objectForName:SDLNameCommandId];
 }
 
-- (void)setMenuParams:(SDLMenuParams *)menuParams {
+- (void)setMenuParams:(nullable SDLMenuParams *)menuParams {
     [parameters sdl_setObject:menuParams forName:SDLNameMenuParams];
 }
 
-- (SDLMenuParams *)menuParams {
+- (nullable SDLMenuParams *)menuParams {
     return [parameters sdl_objectForName:SDLNameMenuParams ofClass:SDLMenuParams.class];
 }
 
-- (void)setVrCommands:(NSMutableArray<NSString *> *)vrCommands {
+- (void)setVrCommands:(nullable NSMutableArray<NSString *> *)vrCommands {
     [parameters sdl_setObject:vrCommands forName:SDLNameVRCommands];
 }
 
-- (NSMutableArray<NSString *> *)vrCommands {
+- (nullable NSMutableArray<NSString *> *)vrCommands {
     return [parameters sdl_objectForName:SDLNameVRCommands];
 }
 
-- (void)setCmdIcon:(SDLImage *)cmdIcon {
+- (void)setCmdIcon:(nullable SDLImage *)cmdIcon {
     [parameters sdl_setObject:cmdIcon forName:SDLNameCommandIcon];
 }
 
-- (SDLImage *)cmdIcon {
+- (nullable SDLImage *)cmdIcon {
     return [parameters sdl_objectForName:SDLNameCommandIcon ofClass:SDLImage.class];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLAddCommandResponse.h b/SmartDeviceLink/SDLAddCommandResponse.h
index ee037f281..554f59d82 100644
--- a/SmartDeviceLink/SDLAddCommandResponse.h
+++ b/SmartDeviceLink/SDLAddCommandResponse.h
@@ -9,6 +9,11 @@
  *
  * Since <b>SmartDeviceLink 1.0</b>
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLAddCommandResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLAddCommandResponse.m b/SmartDeviceLink/SDLAddCommandResponse.m
index d7f5a725c..877b189ec 100644
--- a/SmartDeviceLink/SDLAddCommandResponse.m
+++ b/SmartDeviceLink/SDLAddCommandResponse.m
@@ -5,6 +5,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLAddCommandResponse
 
 - (instancetype)init {
@@ -14,3 +16,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLAddSubMenu.h b/SmartDeviceLink/SDLAddSubMenu.h
index 6fe0c349d..b411a43bd 100644
--- a/SmartDeviceLink/SDLAddSubMenu.h
+++ b/SmartDeviceLink/SDLAddSubMenu.h
@@ -16,6 +16,9 @@
  * Since <b>SmartDeviceLink 1.0</b><br>
  * see SDLDeleteSubMenu SDLAddCommand SDLDeleteCommand
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLAddSubMenu : SDLRPCRequest
 
 - (instancetype)initWithId:(UInt32)menuId menuName:(NSString *)menuName;
@@ -28,7 +31,7 @@
  * <i>SDLAddCommand</i> to which SDLSubMenu is the parent of the command being added
  * <p>
  */
-@property (strong) NSNumber<SDLInt> *menuID;
+@property (strong, nonatomic) NSNumber<SDLInt> *menuID;
 /**
  * @abstract a position of menu
  * @discussion An NSNumber pointer representing the position within the items
@@ -47,11 +50,13 @@
  *            the end of the list</li>
  *            </ul>
  */
-@property (strong) NSNumber<SDLInt> *position;
+@property (nullable, strong, nonatomic) NSNumber<SDLInt> *position;
 /**
  * @abstract a menuName which is displayed representing this submenu item
  * @discussion NSString which will be displayed representing this submenu item
  */
-@property (strong) NSString *menuName;
+@property (strong, nonatomic) NSString *menuName;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLAddSubMenu.m b/SmartDeviceLink/SDLAddSubMenu.m
index 02a52b8a5..4f8ef5109 100644
--- a/SmartDeviceLink/SDLAddSubMenu.m
+++ b/SmartDeviceLink/SDLAddSubMenu.m
@@ -5,6 +5,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLAddSubMenu
 
 - (instancetype)init {
@@ -45,11 +47,11 @@
     return [parameters sdl_objectForName:SDLNameMenuId];
 }
 
-- (void)setPosition:(NSNumber<SDLInt> *)position {
+- (void)setPosition:(nullable NSNumber<SDLInt> *)position {
     [parameters sdl_setObject:position forName:SDLNamePosition];
 }
 
-- (NSNumber<SDLInt> *)position {
+- (nullable NSNumber<SDLInt> *)position {
     return [parameters sdl_objectForName:SDLNamePosition];
 }
 
@@ -62,3 +64,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLAddSubMenuResponse.h b/SmartDeviceLink/SDLAddSubMenuResponse.h
index b3124433b..17305aace 100644
--- a/SmartDeviceLink/SDLAddSubMenuResponse.h
+++ b/SmartDeviceLink/SDLAddSubMenuResponse.h
@@ -7,6 +7,11 @@
  * SDLAddSubMenuResponse is sent, when SDLAddSubMenu has been called
  * Since <b>SmartDeviceLink 1.0</b>
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLAddSubMenuResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLAddSubMenuResponse.m b/SmartDeviceLink/SDLAddSubMenuResponse.m
index 3f2c86c24..41ab1d8ce 100644
--- a/SmartDeviceLink/SDLAddSubMenuResponse.m
+++ b/SmartDeviceLink/SDLAddSubMenuResponse.m
@@ -5,6 +5,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLAddSubMenuResponse
 
 - (instancetype)init {
@@ -14,3 +16,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLAirbagStatus.h b/SmartDeviceLink/SDLAirbagStatus.h
index a8d127f17..ce10945c7 100644
--- a/SmartDeviceLink/SDLAirbagStatus.h
+++ b/SmartDeviceLink/SDLAirbagStatus.h
@@ -5,15 +5,19 @@
 
 #import "SDLVehicleDataEventStatus.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLAirbagStatus : SDLRPCStruct
 
-@property (strong) SDLVehicleDataEventStatus driverAirbagDeployed;
-@property (strong) SDLVehicleDataEventStatus driverSideAirbagDeployed;
-@property (strong) SDLVehicleDataEventStatus driverCurtainAirbagDeployed;
-@property (strong) SDLVehicleDataEventStatus passengerAirbagDeployed;
-@property (strong) SDLVehicleDataEventStatus passengerCurtainAirbagDeployed;
-@property (strong) SDLVehicleDataEventStatus driverKneeAirbagDeployed;
-@property (strong) SDLVehicleDataEventStatus passengerSideAirbagDeployed;
-@property (strong) SDLVehicleDataEventStatus passengerKneeAirbagDeployed;
+@property (strong, nonatomic) SDLVehicleDataEventStatus driverAirbagDeployed;
+@property (strong, nonatomic) SDLVehicleDataEventStatus driverSideAirbagDeployed;
+@property (strong, nonatomic) SDLVehicleDataEventStatus driverCurtainAirbagDeployed;
+@property (strong, nonatomic) SDLVehicleDataEventStatus passengerAirbagDeployed;
+@property (strong, nonatomic) SDLVehicleDataEventStatus passengerCurtainAirbagDeployed;
+@property (strong, nonatomic) SDLVehicleDataEventStatus driverKneeAirbagDeployed;
+@property (strong, nonatomic) SDLVehicleDataEventStatus passengerSideAirbagDeployed;
+@property (strong, nonatomic) SDLVehicleDataEventStatus passengerKneeAirbagDeployed;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLAirbagStatus.m b/SmartDeviceLink/SDLAirbagStatus.m
index ca4981849..453d08304 100644
--- a/SmartDeviceLink/SDLAirbagStatus.m
+++ b/SmartDeviceLink/SDLAirbagStatus.m
@@ -5,6 +5,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLAirbagStatus
 
 - (void)setDriverAirbagDeployed:(SDLVehicleDataEventStatus)driverAirbagDeployed {
@@ -71,3 +73,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLAlert.h b/SmartDeviceLink/SDLAlert.h
index f6b0b324a..22b4e9d50 100644
--- a/SmartDeviceLink/SDLAlert.h
+++ b/SmartDeviceLink/SDLAlert.h
@@ -35,28 +35,31 @@
  *
  * @since SDL 1.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLAlert : SDLRPCRequest
 
 
-- (instancetype)initWithAlertText1:(NSString *)alertText1 alertText2:(NSString *)alertText2 duration:(UInt16)duration;
+- (instancetype)initWithAlertText1:(nullable NSString *)alertText1 alertText2:(nullable NSString *)alertText2 duration:(UInt16)duration;
 
-- (instancetype)initWithAlertText1:(NSString *)alertText1 alertText2:(NSString *)alertText2 alertText3:(NSString *)alertText3;
+- (instancetype)initWithAlertText1:(nullable NSString *)alertText1 alertText2:(nullable NSString *)alertText2 alertText3:(nullable NSString *)alertText3;
 
-- (instancetype)initWithAlertText1:(NSString *)alertText1 alertText2:(NSString *)alertText2 alertText3:(NSString *)alertText3 duration:(UInt16)duration;
+- (instancetype)initWithAlertText1:(nullable NSString *)alertText1 alertText2:(nullable NSString *)alertText2 alertText3:(nullable NSString *)alertText3 duration:(UInt16)duration;
 
-- (instancetype)initWithAlertText1:(NSString *)alertText1 alertText2:(NSString *)alertText2 alertText3:(NSString *)alertText3 duration:(UInt16)duration softButtons:(NSArray<SDLSoftButton *> *)softButtons;
+- (instancetype)initWithAlertText1:(nullable NSString *)alertText1 alertText2:(nullable NSString *)alertText2 alertText3:(nullable NSString *)alertText3 duration:(UInt16)duration softButtons:(nullable NSArray<SDLSoftButton *> *)softButtons;
 
-- (instancetype)initWithTTS:(NSString *)ttsText playTone:(BOOL)playTone;
+- (instancetype)initWithTTS:(nullable NSString *)ttsText playTone:(BOOL)playTone;
 
-- (instancetype)initWithTTS:(NSString *)ttsText alertText1:(NSString *)alertText1 alertText2:(NSString *)alertText2 playTone:(BOOL)playTone duration:(UInt16)duration;
+- (instancetype)initWithTTS:(nullable NSString *)ttsText alertText1:(nullable NSString *)alertText1 alertText2:(nullable NSString *)alertText2 playTone:(BOOL)playTone duration:(UInt16)duration;
 
-- (instancetype)initWithTTS:(NSString *)ttsText alertText1:(NSString *)alertText1 alertText2:(NSString *)alertText2 alertText3:(NSString *)alertText3 playTone:(BOOL)playTone duration:(UInt16)duration;
+- (instancetype)initWithTTS:(nullable NSString *)ttsText alertText1:(nullable NSString *)alertText1 alertText2:(nullable NSString *)alertText2 alertText3:(nullable NSString *)alertText3 playTone:(BOOL)playTone duration:(UInt16)duration;
 
-- (instancetype)initWithTTSChunks:(NSArray<SDLTTSChunk *> *)ttsChunks playTone:(BOOL)playTone;
+- (instancetype)initWithTTSChunks:(nullable NSArray<SDLTTSChunk *> *)ttsChunks playTone:(BOOL)playTone;
 
-- (instancetype)initWithTTSChunks:(NSArray<SDLTTSChunk *> *)ttsChunks alertText1:(NSString *)alertText1 alertText2:(NSString *)alertText2 alertText3:(NSString *)alertText3 playTone:(BOOL)playTone softButtons:(NSArray<SDLSoftButton *> *)softButtons;
+- (instancetype)initWithTTSChunks:(nullable NSArray<SDLTTSChunk *> *)ttsChunks alertText1:(nullable NSString *)alertText1 alertText2:(nullable NSString *)alertText2 alertText3:(nullable NSString *)alertText3 playTone:(BOOL)playTone softButtons:(nullable NSArray<SDLSoftButton *> *)softButtons;
 
-- (instancetype)initWithTTSChunks:(NSArray<SDLTTSChunk *> *)ttsChunks alertText1:(NSString *)alertText1 alertText2:(NSString *)alertText2 alertText3:(NSString *)alertText3 playTone:(BOOL)playTone duration:(UInt16)duration softButtons:(NSArray<SDLSoftButton *> *)softButtons;
+- (instancetype)initWithTTSChunks:(nullable NSArray<SDLTTSChunk *> *)ttsChunks alertText1:(nullable NSString *)alertText1 alertText2:(nullable NSString *)alertText2 alertText3:(nullable NSString *)alertText3 playTone:(BOOL)playTone duration:(UInt16)duration softButtons:(nullable NSArray<SDLSoftButton *> *)softButtons;
 
 
 /**
@@ -70,7 +73,7 @@
  *
  * Optional, Max length 500 chars
  */
-@property (strong) NSString *alertText1;
+@property (nullable, strong, nonatomic) NSString *alertText1;
 
 /**
  * @abstract The String to be displayed in the second field of the display during the Alert
@@ -85,7 +88,7 @@
  *
  * Optional, Max length 500 chars
  */
-@property (strong) NSString *alertText2;
+@property (nullable, strong, nonatomic) NSString *alertText2;
 
 /**
  * @abstract the String to be displayed in the third field of the display during the Alert
@@ -99,7 +102,7 @@
  *
  * Optional, Max length 500 chars
  */
-@property (strong) NSString *alertText3;
+@property (nullable, strong, nonatomic) NSString *alertText3;
 
 /**
  * @abstract An array which, taken together, specify what is to be spoken to the user
@@ -108,7 +111,7 @@
  *
  * @see SDLTTSChunk
  */
-@property (strong) NSMutableArray<SDLTTSChunk *> *ttsChunks;
+@property (nullable, strong, nonatomic) NSMutableArray<SDLTTSChunk *> *ttsChunks;
 
 /**
  * @abstract The duration of the displayed portion of the alert, in milliseconds.
@@ -121,7 +124,7 @@
  * 
  * Optional, Integer, 3000 - 10000
  */
-@property (strong) NSNumber<SDLInt> *duration;
+@property (nullable, strong, nonatomic) NSNumber<SDLInt> *duration;
 
 /**
  * @abstract Whether the alert tone should be played before the TTS (if any) is spoken.
@@ -130,7 +133,7 @@
  * 
  * Optional, Boolean
  */
-@property (strong) NSNumber<SDLBool> *playTone;
+@property (nullable, strong, nonatomic) NSNumber<SDLBool> *playTone;
 
 /**
  * @abstract If supported on the given platform, the alert GUI will include some sort of animation indicating that loading of a feature is progressing.  e.g. a spinning wheel or hourglass, etc.
@@ -139,7 +142,7 @@
  *
  * @since SmartDeviceLink 2.0
  */
-@property (strong) NSNumber<SDLBool> *progressIndicator;
+@property (nullable, strong, nonatomic) NSNumber<SDLBool> *progressIndicator;
 
 /**
  * @abstract App defined SoftButtons.
@@ -150,6 +153,8 @@
  *
  * @see SDLSoftButton
  */
-@property (strong) NSMutableArray<SDLSoftButton *> *softButtons;
+@property (nullable, strong, nonatomic) NSMutableArray<SDLSoftButton *> *softButtons;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLAlert.m b/SmartDeviceLink/SDLAlert.m
index 98ec9f562..2b5640505 100644
--- a/SmartDeviceLink/SDLAlert.m
+++ b/SmartDeviceLink/SDLAlert.m
@@ -9,6 +9,8 @@
 
 static UInt16 const SDLDefaultDuration = 5000;
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLAlert
 
 - (instancetype)init {
@@ -17,44 +19,44 @@ static UInt16 const SDLDefaultDuration = 5000;
     return self;
 }
 
-- (instancetype)initWithAlertText1:(NSString *)alertText1 alertText2:(NSString *)alertText2 alertText3:(NSString *)alertText3 {
+- (instancetype)initWithAlertText1:(nullable NSString *)alertText1 alertText2:(nullable NSString *)alertText2 alertText3:(nullable NSString *)alertText3 {
     return [self initWithAlertText1:alertText1 alertText2:alertText2 alertText3:alertText3 duration:SDLDefaultDuration];
 }
 
-- (instancetype)initWithAlertText1:(NSString *)alertText1 alertText2:(NSString *)alertText2 duration:(UInt16)duration {
+- (instancetype)initWithAlertText1:(nullable NSString *)alertText1 alertText2:(nullable NSString *)alertText2 duration:(UInt16)duration {
     return [self initWithAlertText1:alertText1 alertText2:alertText2 alertText3:nil duration:duration];
 }
 
-- (instancetype)initWithAlertText1:(NSString *)alertText1 alertText2:(NSString *)alertText2 alertText3:(NSString *)alertText3 duration:(UInt16)duration {
+- (instancetype)initWithAlertText1:(nullable NSString *)alertText1 alertText2:(nullable NSString *)alertText2 alertText3:(nullable NSString *)alertText3 duration:(UInt16)duration {
     return [self initWithAlertText1:alertText1 alertText2:alertText2 alertText3:alertText3 duration:duration softButtons:nil];
 }
 
-- (instancetype)initWithAlertText1:(NSString *)alertText1 alertText2:(NSString *)alertText2 alertText3:(NSString *)alertText3 duration:(UInt16)duration softButtons:(NSArray<SDLSoftButton *> *)softButtons {
+- (instancetype)initWithAlertText1:(nullable NSString *)alertText1 alertText2:(nullable NSString *)alertText2 alertText3:(nullable NSString *)alertText3 duration:(UInt16)duration softButtons:(nullable NSArray<SDLSoftButton *> *)softButtons {
     return [self initWithTTSChunks:nil alertText1:alertText1 alertText2:alertText2 alertText3:alertText3 playTone:NO duration:duration softButtons:softButtons];
 }
 
-- (instancetype)initWithTTS:(NSString *)ttsText playTone:(BOOL)playTone {
+- (instancetype)initWithTTS:(nullable NSString *)ttsText playTone:(BOOL)playTone {
     return [self initWithTTS:ttsText alertText1:nil alertText2:nil playTone:playTone duration:SDLDefaultDuration];
 }
 
-- (instancetype)initWithTTS:(NSString *)ttsText alertText1:(NSString *)alertText1 alertText2:(NSString *)alertText2 playTone:(BOOL)playTone duration:(UInt16)duration {
+- (instancetype)initWithTTS:(nullable NSString *)ttsText alertText1:(nullable NSString *)alertText1 alertText2:(nullable NSString *)alertText2 playTone:(BOOL)playTone duration:(UInt16)duration {
     return [self initWithTTS:ttsText alertText1:alertText1 alertText2:alertText2 alertText3:nil playTone:playTone duration:duration];
 }
 
-- (instancetype)initWithTTS:(NSString *)ttsText alertText1:(NSString *)alertText1 alertText2:(NSString *)alertText2 alertText3:(NSString *)alertText3 playTone:(BOOL)playTone duration:(UInt16)duration {
+- (instancetype)initWithTTS:(nullable NSString *)ttsText alertText1:(nullable NSString *)alertText1 alertText2:(nullable NSString *)alertText2 alertText3:(nullable NSString *)alertText3 playTone:(BOOL)playTone duration:(UInt16)duration {
     NSMutableArray *ttsChunks = [SDLTTSChunk textChunksFromString:ttsText];
     return [self initWithTTSChunks:ttsChunks alertText1:alertText1 alertText2:alertText2 alertText3:alertText3 playTone:playTone duration:duration softButtons:nil];
 }
 
-- (instancetype)initWithTTSChunks:(NSArray<SDLTTSChunk *> *)ttsChunks playTone:(BOOL)playTone {
+- (instancetype)initWithTTSChunks:(nullable NSArray<SDLTTSChunk *> *)ttsChunks playTone:(BOOL)playTone {
     return [self initWithTTSChunks:ttsChunks alertText1:nil alertText2:nil alertText3:nil playTone:playTone duration:SDLDefaultDuration softButtons:nil];
 }
 
-- (instancetype)initWithTTSChunks:(NSArray<SDLTTSChunk *> *)ttsChunks alertText1:(NSString *)alertText1 alertText2:(NSString *)alertText2 alertText3:(NSString *)alertText3 playTone:(BOOL)playTone softButtons:(NSArray<SDLSoftButton *> *)softButtons {
+- (instancetype)initWithTTSChunks:(nullable NSArray<SDLTTSChunk *> *)ttsChunks alertText1:(nullable NSString *)alertText1 alertText2:(nullable NSString *)alertText2 alertText3:(nullable NSString *)alertText3 playTone:(BOOL)playTone softButtons:(nullable NSArray<SDLSoftButton *> *)softButtons {
     return [self initWithTTSChunks:ttsChunks alertText1:alertText1 alertText2:alertText2 alertText3:alertText3 playTone:playTone duration:SDLDefaultDuration softButtons:softButtons];
 }
 
-- (instancetype)initWithTTSChunks:(NSArray<SDLTTSChunk *> *)ttsChunks alertText1:(NSString *)alertText1 alertText2:(NSString *)alertText2 alertText3:(NSString *)alertText3 playTone:(BOOL)playTone duration:(UInt16)duration softButtons:(NSArray<SDLSoftButton *> *)softButtons {
+- (instancetype)initWithTTSChunks:(nullable NSArray<SDLTTSChunk *> *)ttsChunks alertText1:(nullable NSString *)alertText1 alertText2:(nullable NSString *)alertText2 alertText3:(nullable NSString *)alertText3 playTone:(BOOL)playTone duration:(UInt16)duration softButtons:(nullable NSArray<SDLSoftButton *> *)softButtons {
     self = [self init];
     if (!self) {
         return nil;
@@ -71,68 +73,70 @@ static UInt16 const SDLDefaultDuration = 5000;
     return self;
 }
 
-- (void)setAlertText1:(NSString *)alertText1 {
+- (void)setAlertText1:(nullable NSString *)alertText1 {
     [parameters sdl_setObject:alertText1 forName:SDLNameAlertText1];
 }
 
-- (NSString *)alertText1 {
+- (nullable NSString *)alertText1 {
     return [parameters sdl_objectForName:SDLNameAlertText1];
 }
 
-- (void)setAlertText2:(NSString *)alertText2 {
+- (void)setAlertText2:(nullable NSString *)alertText2 {
     [parameters sdl_setObject:alertText2 forName:SDLNameAlertText2];
 }
 
-- (NSString *)alertText2 {
+- (nullable NSString *)alertText2 {
     return [parameters sdl_objectForName:SDLNameAlertText2];
 }
 
-- (void)setAlertText3:(NSString *)alertText3 {
+- (void)setAlertText3:(nullable NSString *)alertText3 {
     [parameters sdl_setObject:alertText3 forName:SDLNameAlertText3];
 }
 
-- (NSString *)alertText3 {
+- (nullable NSString *)alertText3 {
     return [parameters sdl_objectForName:SDLNameAlertText3];
 }
 
-- (void)setTtsChunks:(NSMutableArray<SDLTTSChunk *> *)ttsChunks {
+- (void)setTtsChunks:(nullable NSMutableArray<SDLTTSChunk *> *)ttsChunks {
     [parameters sdl_setObject:ttsChunks forName:SDLNameTTSChunks];
 }
 
-- (NSMutableArray<SDLTTSChunk *> *)ttsChunks {
+- (nullable NSMutableArray<SDLTTSChunk *> *)ttsChunks {
     return [parameters sdl_objectsForName:SDLNameTTSChunks ofClass:SDLTTSChunk.class];
 }
 
-- (void)setDuration:(NSNumber<SDLInt> *)duration {
+- (void)setDuration:(nullable NSNumber<SDLInt> *)duration {
     [parameters sdl_setObject:duration forName:SDLNameDuration];
 }
 
-- (NSNumber<SDLInt> *)duration {
+- (nullable NSNumber<SDLInt> *)duration {
     return [parameters sdl_objectForName:SDLNameDuration];
 }
 
-- (void)setPlayTone:(NSNumber<SDLBool> *)playTone {
+- (void)setPlayTone:(nullable NSNumber<SDLBool> *)playTone {
     [parameters sdl_setObject:playTone forName:SDLNamePlayTone];
 }
 
-- (NSNumber<SDLBool> *)playTone {
+- (nullable NSNumber<SDLBool> *)playTone {
     return [parameters sdl_objectForName:SDLNamePlayTone];
 }
 
-- (void)setProgressIndicator:(NSNumber<SDLBool> *)progressIndicator {
+- (void)setProgressIndicator:(nullable NSNumber<SDLBool> *)progressIndicator {
     [parameters sdl_setObject:progressIndicator forName:SDLNameProgressIndicator];
 }
 
-- (NSNumber<SDLBool> *)progressIndicator {
+- (nullable NSNumber<SDLBool> *)progressIndicator {
     return [parameters sdl_objectForName:SDLNameProgressIndicator];
 }
 
-- (void)setSoftButtons:(NSMutableArray<SDLSoftButton *> *)softButtons {
+- (void)setSoftButtons:(nullable NSMutableArray<SDLSoftButton *> *)softButtons {
     [parameters sdl_setObject:softButtons forName:SDLNameSoftButtons];
 }
 
-- (NSMutableArray<SDLSoftButton *> *)softButtons {
+- (nullable NSMutableArray<SDLSoftButton *> *)softButtons {
     return [parameters sdl_objectsForName:SDLNameSoftButtons ofClass:SDLSoftButton.class];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLAlertManeuver.h b/SmartDeviceLink/SDLAlertManeuver.h
index 35e3630ba..66baa8585 100644
--- a/SmartDeviceLink/SDLAlertManeuver.h
+++ b/SmartDeviceLink/SDLAlertManeuver.h
@@ -11,12 +11,17 @@
 /**
  *  @since SmartDeviceLink 1.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLAlertManeuver : SDLRPCRequest
 
-- (instancetype)initWithTTS:(NSString *)ttsText softButtons:(NSArray<SDLSoftButton *> *)softButtons;
-- (instancetype)initWithTTSChunks:(NSArray<SDLTTSChunk *> *)ttsChunks softButtons:(NSArray<SDLSoftButton *> *)softButtons;
+- (instancetype)initWithTTS:(nullable NSString *)ttsText softButtons:(nullable NSArray<SDLSoftButton *> *)softButtons;
+- (instancetype)initWithTTSChunks:(nullable NSArray<SDLTTSChunk *> *)ttsChunks softButtons:(nullable NSArray<SDLSoftButton *> *)softButtons;
 
-@property (strong) NSMutableArray<SDLTTSChunk *> *ttsChunks;
-@property (strong) NSMutableArray<SDLSoftButton *> *softButtons;
+@property (nullable, strong, nonatomic) NSMutableArray<SDLTTSChunk *> *ttsChunks;
+@property (nullable, strong, nonatomic) NSMutableArray<SDLSoftButton *> *softButtons;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLAlertManeuver.m b/SmartDeviceLink/SDLAlertManeuver.m
index 0c2b58d67..433669cab 100644
--- a/SmartDeviceLink/SDLAlertManeuver.m
+++ b/SmartDeviceLink/SDLAlertManeuver.m
@@ -9,6 +9,8 @@
 #import "SDLSoftButton.h"
 #import "SDLTTSChunk.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLAlertManeuver
 
 - (instancetype)init {
@@ -18,12 +20,12 @@
 }
 
 
-- (instancetype)initWithTTS:(NSString *)ttsText softButtons:(NSArray<SDLSoftButton *> *)softButtons {
+- (instancetype)initWithTTS:(nullable NSString *)ttsText softButtons:(nullable NSArray<SDLSoftButton *> *)softButtons {
     NSMutableArray *ttsChunks = [SDLTTSChunk textChunksFromString:ttsText];
     return [self initWithTTSChunks:ttsChunks softButtons:softButtons];
 }
 
-- (instancetype)initWithTTSChunks:(NSArray<SDLTTSChunk *> *)ttsChunks softButtons:(NSArray<SDLSoftButton *> *)softButtons {
+- (instancetype)initWithTTSChunks:(nullable NSArray<SDLTTSChunk *> *)ttsChunks softButtons:(nullable NSArray<SDLSoftButton *> *)softButtons {
     self = [self init];
     if (!self) {
         return nil;
@@ -35,20 +37,22 @@
     return self;
 }
 
-- (void)setTtsChunks:(NSMutableArray<SDLTTSChunk *> *)ttsChunks {
+- (void)setTtsChunks:(nullable NSMutableArray<SDLTTSChunk *> *)ttsChunks {
     [parameters sdl_setObject:ttsChunks forName:SDLNameTTSChunks];
 }
 
-- (NSMutableArray<SDLTTSChunk *> *)ttsChunks {
+- (nullable NSMutableArray<SDLTTSChunk *> *)ttsChunks {
     return [parameters sdl_objectsForName:SDLNameTTSChunks ofClass:SDLTTSChunk.class];
 }
 
-- (void)setSoftButtons:(NSMutableArray<SDLSoftButton *> *)softButtons {
+- (void)setSoftButtons:(nullable NSMutableArray<SDLSoftButton *> *)softButtons {
     [parameters sdl_setObject:softButtons forName:SDLNameSoftButtons];
 }
 
-- (NSMutableArray<SDLSoftButton *> *)softButtons {
+- (nullable NSMutableArray<SDLSoftButton *> *)softButtons {
     return [parameters sdl_objectsForName:SDLNameSoftButtons ofClass:SDLSoftButton.class];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLAlertManeuverResponse.h b/SmartDeviceLink/SDLAlertManeuverResponse.h
index 41dcaaa5e..d541cde0e 100644
--- a/SmartDeviceLink/SDLAlertManeuverResponse.h
+++ b/SmartDeviceLink/SDLAlertManeuverResponse.h
@@ -7,6 +7,11 @@
 /** SDLAlertManeuverResponse is sent, when SDLAlertManeuver has been called.
  * @since SmartDeviceLink 1.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLAlertManeuverResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLAlertManeuverResponse.m b/SmartDeviceLink/SDLAlertManeuverResponse.m
index 020337d3a..99cc21cf5 100644
--- a/SmartDeviceLink/SDLAlertManeuverResponse.m
+++ b/SmartDeviceLink/SDLAlertManeuverResponse.m
@@ -6,6 +6,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLAlertManeuverResponse
 
 - (instancetype)init {
@@ -15,3 +17,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLAlertResponse.h b/SmartDeviceLink/SDLAlertResponse.h
index beca991f1..a2883778c 100644
--- a/SmartDeviceLink/SDLAlertResponse.h
+++ b/SmartDeviceLink/SDLAlertResponse.h
@@ -8,8 +8,13 @@
  * Sent after SDLAlert has been sent
  * @since SDL 1.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLAlertResponse : SDLRPCResponse
 
-@property (strong) NSNumber<SDLInt> *tryAgainTime;
+@property (nullable, strong, nonatomic) NSNumber<SDLInt> *tryAgainTime;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLAlertResponse.m b/SmartDeviceLink/SDLAlertResponse.m
index d067c40aa..f93a124e7 100644
--- a/SmartDeviceLink/SDLAlertResponse.m
+++ b/SmartDeviceLink/SDLAlertResponse.m
@@ -6,6 +6,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLAlertResponse
 
 - (instancetype)init {
@@ -14,11 +16,13 @@
     return self;
 }
 
-- (void)setTryAgainTime:(NSNumber<SDLInt> *)tryAgainTime {
+- (void)setTryAgainTime:(nullable NSNumber<SDLInt> *)tryAgainTime {
     [parameters sdl_setObject:tryAgainTime forName:SDLNameTryAgainTime];}
 
-- (NSNumber<SDLInt> *)tryAgainTime {
+- (nullable NSNumber<SDLInt> *)tryAgainTime {
     return [parameters objectForKey:SDLNameTryAgainTime];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLAppInfo.h b/SmartDeviceLink/SDLAppInfo.h
index c08fba9fd..98a573970 100644
--- a/SmartDeviceLink/SDLAppInfo.h
+++ b/SmartDeviceLink/SDLAppInfo.h
@@ -3,12 +3,16 @@
 
 #import "SDLRPCStruct.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLAppInfo : SDLRPCStruct
 
 + (instancetype)currentAppInfo;
 
-@property (strong) NSString *appDisplayName;
-@property (strong) NSString *appBundleID;
-@property (strong) NSString *appVersion;
+@property (strong, nonatomic) NSString *appDisplayName;
+@property (strong, nonatomic) NSString *appBundleID;
+@property (strong, nonatomic) NSString *appVersion;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLAppInfo.m b/SmartDeviceLink/SDLAppInfo.m
index f0d3f22af..a9102d40e 100644
--- a/SmartDeviceLink/SDLAppInfo.m
+++ b/SmartDeviceLink/SDLAppInfo.m
@@ -9,6 +9,8 @@
 static NSString *const SDLBundleShortVersionStringKey = @"CFBundleShortVersionString";
 static NSString *const SDLBundleAppNameKey = @"CFBundleName";
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLAppInfo
 
 + (instancetype)currentAppInfo {
@@ -49,3 +51,5 @@ static NSString *const SDLBundleAppNameKey = @"CFBundleName";
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLAudioPassThruCapabilities.h b/SmartDeviceLink/SDLAudioPassThruCapabilities.h
index 08501ff30..f4f14b598 100644
--- a/SmartDeviceLink/SDLAudioPassThruCapabilities.h
+++ b/SmartDeviceLink/SDLAudioPassThruCapabilities.h
@@ -42,22 +42,27 @@
  *  </table>
  * Since <b>SmartDeviceLink 2.0</b>
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLAudioPassThruCapabilities : SDLRPCStruct
 
 /**
  * @abstract The sampling rate for AudioPassThru<br>
  *
  */
-@property (strong) SDLSamplingRate samplingRate;
+@property (strong, nonatomic) SDLSamplingRate samplingRate;
 /**
  * @abstract The sample depth in bit for AudioPassThru<br>
  *
  */
-@property (strong) SDLBitsPerSample bitsPerSample;
+@property (strong, nonatomic) SDLBitsPerSample bitsPerSample;
 /**
  * @abstract The audiotype for AudioPassThru<br>
  *
  */
-@property (strong) SDLAudioType audioType;
+@property (strong, nonatomic) SDLAudioType audioType;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLAudioPassThruCapabilities.m b/SmartDeviceLink/SDLAudioPassThruCapabilities.m
index eb8555eff..268170757 100644
--- a/SmartDeviceLink/SDLAudioPassThruCapabilities.m
+++ b/SmartDeviceLink/SDLAudioPassThruCapabilities.m
@@ -7,6 +7,7 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
 
 @implementation SDLAudioPassThruCapabilities
 
@@ -35,3 +36,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLBeltStatus.h b/SmartDeviceLink/SDLBeltStatus.h
index 6fd565877..9b60b9dc7 100644
--- a/SmartDeviceLink/SDLBeltStatus.h
+++ b/SmartDeviceLink/SDLBeltStatus.h
@@ -5,22 +5,26 @@
 
 #import "SDLVehicleDataEventStatus.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLBeltStatus : SDLRPCStruct
 
-@property (strong) SDLVehicleDataEventStatus driverBeltDeployed;
-@property (strong) SDLVehicleDataEventStatus passengerBeltDeployed;
-@property (strong) SDLVehicleDataEventStatus passengerBuckleBelted;
-@property (strong) SDLVehicleDataEventStatus driverBuckleBelted;
-@property (strong) SDLVehicleDataEventStatus leftRow2BuckleBelted;
-@property (strong) SDLVehicleDataEventStatus passengerChildDetected;
-@property (strong) SDLVehicleDataEventStatus rightRow2BuckleBelted;
-@property (strong) SDLVehicleDataEventStatus middleRow2BuckleBelted;
-@property (strong) SDLVehicleDataEventStatus middleRow3BuckleBelted;
-@property (strong) SDLVehicleDataEventStatus leftRow3BuckleBelted;
-@property (strong) SDLVehicleDataEventStatus rightRow3BuckleBelted;
-@property (strong) SDLVehicleDataEventStatus leftRearInflatableBelted;
-@property (strong) SDLVehicleDataEventStatus rightRearInflatableBelted;
-@property (strong) SDLVehicleDataEventStatus middleRow1BeltDeployed;
-@property (strong) SDLVehicleDataEventStatus middleRow1BuckleBelted;
+@property (strong, nonatomic) SDLVehicleDataEventStatus driverBeltDeployed;
+@property (strong, nonatomic) SDLVehicleDataEventStatus passengerBeltDeployed;
+@property (strong, nonatomic) SDLVehicleDataEventStatus passengerBuckleBelted;
+@property (strong, nonatomic) SDLVehicleDataEventStatus driverBuckleBelted;
+@property (strong, nonatomic) SDLVehicleDataEventStatus leftRow2BuckleBelted;
+@property (strong, nonatomic) SDLVehicleDataEventStatus passengerChildDetected;
+@property (strong, nonatomic) SDLVehicleDataEventStatus rightRow2BuckleBelted;
+@property (strong, nonatomic) SDLVehicleDataEventStatus middleRow2BuckleBelted;
+@property (strong, nonatomic) SDLVehicleDataEventStatus middleRow3BuckleBelted;
+@property (strong, nonatomic) SDLVehicleDataEventStatus leftRow3BuckleBelted;
+@property (strong, nonatomic) SDLVehicleDataEventStatus rightRow3BuckleBelted;
+@property (strong, nonatomic) SDLVehicleDataEventStatus leftRearInflatableBelted;
+@property (strong, nonatomic) SDLVehicleDataEventStatus rightRearInflatableBelted;
+@property (strong, nonatomic) SDLVehicleDataEventStatus middleRow1BeltDeployed;
+@property (strong, nonatomic) SDLVehicleDataEventStatus middleRow1BuckleBelted;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLBeltStatus.m b/SmartDeviceLink/SDLBeltStatus.m
index 3ee50c7bf..d65a1fd74 100644
--- a/SmartDeviceLink/SDLBeltStatus.m
+++ b/SmartDeviceLink/SDLBeltStatus.m
@@ -7,6 +7,8 @@
 #import "SDLNames.h"
 #import "SDLVehicleDataEventStatus.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLBeltStatus
 
 - (void)setDriverBeltDeployed:(SDLVehicleDataEventStatus)driverBeltDeployed {
@@ -130,3 +132,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLBodyInformation.h b/SmartDeviceLink/SDLBodyInformation.h
index 4729ffc6c..a0d626b57 100644
--- a/SmartDeviceLink/SDLBodyInformation.h
+++ b/SmartDeviceLink/SDLBodyInformation.h
@@ -10,41 +10,46 @@
 /**
  * The body information including power modes.
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLBodyInformation : SDLRPCStruct
 
 /**
  * @abstract References signal "PrkBrkActv_B_Actl".
  */
-@property (strong) NSNumber<SDLBool> *parkBrakeActive;
+@property (strong, nonatomic) NSNumber<SDLBool> *parkBrakeActive;
 
 /**
  * @abstract References signal "Ignition_Switch_Stable". See IgnitionStableStatus.
  */
-@property (strong) SDLIgnitionStableStatus ignitionStableStatus;
+@property (strong, nonatomic) SDLIgnitionStableStatus ignitionStableStatus;
 
 /**
  * @abstract References signal "Ignition_status". See IgnitionStatus.
  */
-@property (strong) SDLIgnitionStatus ignitionStatus;
+@property (strong, nonatomic) SDLIgnitionStatus ignitionStatus;
 
 /**
  * @abstract References signal "DrStatDrv_B_Actl".
  */
-@property (strong) NSNumber<SDLBool> *driverDoorAjar;
+@property (nullable, strong, nonatomic) NSNumber<SDLBool> *driverDoorAjar;
 
 /**
  * @abstract References signal "DrStatPsngr_B_Actl".
  */
-@property (strong) NSNumber<SDLBool> *passengerDoorAjar;
+@property (nullable, strong, nonatomic) NSNumber<SDLBool> *passengerDoorAjar;
 
 /**
  * @abstract References signal "DrStatRl_B_Actl".
  */
-@property (strong) NSNumber<SDLBool> *rearLeftDoorAjar;
+@property (nullable, strong, nonatomic) NSNumber<SDLBool> *rearLeftDoorAjar;
 
 /**
  * @abstract References signal "DrStatRr_B_Actl".
  */
-@property (strong) NSNumber<SDLBool> *rearRightDoorAjar;
+@property (nullable, strong, nonatomic) NSNumber<SDLBool> *rearRightDoorAjar;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLBodyInformation.m b/SmartDeviceLink/SDLBodyInformation.m
index 3a9bc9b64..3ffbe97c0 100644
--- a/SmartDeviceLink/SDLBodyInformation.m
+++ b/SmartDeviceLink/SDLBodyInformation.m
@@ -9,6 +9,8 @@
 #import "SDLIgnitionStatus.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLBodyInformation
 
 - (void)setParkBrakeActive:(NSNumber<SDLBool> *)parkBrakeActive {
@@ -35,36 +37,38 @@
     return [store sdl_objectForName:SDLNameIgnitionStatus];
 }
 
-- (void)setDriverDoorAjar:(NSNumber<SDLBool> *)driverDoorAjar {
+- (void)setDriverDoorAjar:(nullable NSNumber<SDLBool> *)driverDoorAjar {
     [store sdl_setObject:driverDoorAjar forName:SDLNameDriverDoorAjar];
 }
 
-- (NSNumber<SDLBool> *)driverDoorAjar {
+- (nullable NSNumber<SDLBool> *)driverDoorAjar {
     return [store sdl_objectForName:SDLNameDriverDoorAjar];
 }
 
-- (void)setPassengerDoorAjar:(NSNumber<SDLBool> *)passengerDoorAjar {
+- (void)setPassengerDoorAjar:(nullable NSNumber<SDLBool> *)passengerDoorAjar {
     [store sdl_setObject:passengerDoorAjar forName:SDLNamePassengerDoorAjar];
 }
 
-- (NSNumber<SDLBool> *)passengerDoorAjar {
+- (nullable NSNumber<SDLBool> *)passengerDoorAjar {
     return [store sdl_objectForName:SDLNamePassengerDoorAjar];
 }
 
-- (void)setRearLeftDoorAjar:(NSNumber<SDLBool> *)rearLeftDoorAjar {
+- (void)setRearLeftDoorAjar:(nullable NSNumber<SDLBool> *)rearLeftDoorAjar {
     [store sdl_setObject:rearLeftDoorAjar forName:SDLNameRearLeftDoorAjar];
 }
 
-- (NSNumber<SDLBool> *)rearLeftDoorAjar {
+- (nullable NSNumber<SDLBool> *)rearLeftDoorAjar {
     return [store sdl_objectForName:SDLNameRearLeftDoorAjar];
 }
 
-- (void)setRearRightDoorAjar:(NSNumber<SDLBool> *)rearRightDoorAjar {
+- (void)setRearRightDoorAjar:(nullable NSNumber<SDLBool> *)rearRightDoorAjar {
     [store sdl_setObject:rearRightDoorAjar forName:SDLNameRearRightDoorAjar];
 }
 
-- (NSNumber<SDLBool> *)rearRightDoorAjar {
+- (nullable NSNumber<SDLBool> *)rearRightDoorAjar {
     return [store sdl_objectForName:SDLNameRearRightDoorAjar];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLButtonCapabilities.h b/SmartDeviceLink/SDLButtonCapabilities.h
index f73416239..cc24f84fa 100644
--- a/SmartDeviceLink/SDLButtonCapabilities.h
+++ b/SmartDeviceLink/SDLButtonCapabilities.h
@@ -11,32 +11,37 @@
  * 
  * @since SDL 1.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLButtonCapabilities : SDLRPCStruct
 
 /**
  * @abstract The name of the SDL HMI button.
  */
-@property (strong) SDLButtonName name;
+@property (strong, nonatomic) SDLButtonName name;
 
 /**
  * @abstract A NSNumber value indicates whether the button supports a SHORT press
  *
  * Required, Boolean
  */
-@property (strong) NSNumber<SDLBool> *shortPressAvailable;
+@property (strong, nonatomic) NSNumber<SDLBool> *shortPressAvailable;
 
 /**
  * @abstract A NSNumber value indicates whether the button supports a LONG press
  *
  * Required, Boolean
  */
-@property (strong) NSNumber<SDLBool> *longPressAvailable;
+@property (strong, nonatomic) NSNumber<SDLBool> *longPressAvailable;
 
 /**
  * @abstract A NSNumber value indicates whether the button supports "button down" and "button up"
  *
  * Required, Boolean
  */
-@property (strong) NSNumber<SDLBool> *upDownAvailable;
+@property (strong, nonatomic) NSNumber<SDLBool> *upDownAvailable;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLButtonCapabilities.m b/SmartDeviceLink/SDLButtonCapabilities.m
index 3350ab0f4..42aeb7ae5 100644
--- a/SmartDeviceLink/SDLButtonCapabilities.m
+++ b/SmartDeviceLink/SDLButtonCapabilities.m
@@ -6,6 +6,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLButtonCapabilities
 
 - (void)setName:(SDLButtonName)name {
@@ -41,3 +43,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLChangeRegistration.h b/SmartDeviceLink/SDLChangeRegistration.h
index ed631892f..7f4b06c3c 100644
--- a/SmartDeviceLink/SDLChangeRegistration.h
+++ b/SmartDeviceLink/SDLChangeRegistration.h
@@ -15,11 +15,14 @@
  *
  * @since SDL 2.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLChangeRegistration : SDLRPCRequest
 
 - (instancetype)initWithLanguage:(SDLLanguage)language hmiDisplayLanguage:(SDLLanguage)hmiDisplayLanguage;
 
-- (instancetype)initWithLanguage:(SDLLanguage)language hmiDisplayLanguage:(SDLLanguage)hmiDisplayLanguage appName:(NSString *)appName ttsName:(NSArray<SDLTTSChunk *> *)ttsName ngnMediaScreenAppName:(NSString *)ngnMediaScreenAppName vrSynonyms:(NSArray<NSString *> *)vrSynonyms;
+- (instancetype)initWithLanguage:(SDLLanguage)language hmiDisplayLanguage:(SDLLanguage)hmiDisplayLanguage appName:(nullable NSString *)appName ttsName:(nullable NSArray<SDLTTSChunk *> *)ttsName ngnMediaScreenAppName:(nullable NSString *)ngnMediaScreenAppName vrSynonyms:(nullable NSArray<NSString *> *)vrSynonyms;
 
 /**
  * @abstract The language the app wants to change to
@@ -36,27 +39,29 @@
  *
  *  Optional, Max string length 100 chars
  */
-@property (copy, nonatomic) NSString *appName;
+@property (nullable, copy, nonatomic) NSString *appName;
 
 /**
  *  Request a new TTSName registration.
  *
  *  Optional, Array of SDLTTSChunk, 1 - 100 elements
  */
-@property (copy, nonatomic) NSArray<SDLTTSChunk *> *ttsName;
+@property (nullable, copy, nonatomic) NSArray<SDLTTSChunk *> *ttsName;
 
 /**
  *  Request a new app short name registration
  *
  *  Optional, Max string length 100 chars
  */
-@property (copy, nonatomic) NSString *ngnMediaScreenAppName;
+@property (nullable, copy, nonatomic) NSString *ngnMediaScreenAppName;
 
 /**
  *  Request a new VR synonyms registration
  *
  *  Optional, Array of NSString, 1 - 100 elements, max string length 40 chars
  */
-@property (copy, nonatomic) NSArray<NSString *> *vrSynonyms;
+@property (nullable, copy, nonatomic) NSArray<NSString *> *vrSynonyms;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLChangeRegistration.m b/SmartDeviceLink/SDLChangeRegistration.m
index 713483798..befa2afae 100644
--- a/SmartDeviceLink/SDLChangeRegistration.m
+++ b/SmartDeviceLink/SDLChangeRegistration.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLChangeRegistration
 
 - (instancetype)init {
@@ -24,7 +26,7 @@
     return self;
 }
 
-- (instancetype)initWithLanguage:(SDLLanguage)language hmiDisplayLanguage:(SDLLanguage)hmiDisplayLanguage appName:(NSString *)appName ttsName:(NSArray<SDLTTSChunk *> *)ttsName ngnMediaScreenAppName:(NSString *)ngnMediaScreenAppName vrSynonyms:(NSArray<NSString *> *)vrSynonyms {
+- (instancetype)initWithLanguage:(SDLLanguage)language hmiDisplayLanguage:(SDLLanguage)hmiDisplayLanguage appName:(nullable NSString *)appName ttsName:(nullable NSArray<SDLTTSChunk *> *)ttsName ngnMediaScreenAppName:(nullable NSString *)ngnMediaScreenAppName vrSynonyms:(nullable NSArray<NSString *> *)vrSynonyms {
     self = [self init];
     if (!self) {
         return nil;
@@ -56,36 +58,38 @@
     return [parameters sdl_objectForName:SDLNameHMIDisplayLanguage];
 }
 
-- (void)setAppName:(NSString *)appName {
+- (void)setAppName:(nullable NSString *)appName {
     [parameters sdl_setObject:appName forName:SDLNameAppName];
 }
 
-- (NSString *)appName {
+- (nullable NSString *)appName {
     return [[parameters sdl_objectForName:SDLNameAppName] copy];
 }
 
-- (void)setTtsName:(NSArray<SDLTTSChunk *> *)ttsName {
+- (void)setTtsName:(nullable NSArray<SDLTTSChunk *> *)ttsName {
     [parameters sdl_setObject:ttsName forName:SDLNameTTSName];
 }
 
-- (NSArray<SDLTTSChunk *> *)ttsName {
+- (nullable NSArray<SDLTTSChunk *> *)ttsName {
     return [[parameters sdl_objectForName:SDLNameTTSName] copy];
 }
 
-- (void)setNgnMediaScreenAppName:(NSString *)ngnMediaScreenAppName {
+- (void)setNgnMediaScreenAppName:(nullable NSString *)ngnMediaScreenAppName {
     [parameters sdl_setObject:ngnMediaScreenAppName forName:SDLNameNGNMediaScreenAppName];
 }
 
-- (NSString *)ngnMediaScreenAppName {
+- (nullable NSString *)ngnMediaScreenAppName {
     return [[parameters sdl_objectForName:SDLNameNGNMediaScreenAppName] copy];
 }
 
-- (void)setVrSynonyms:(NSArray<NSString *> *)vrSynonyms {
+- (void)setVrSynonyms:(nullable NSArray<NSString *> *)vrSynonyms {
     [parameters sdl_setObject:vrSynonyms forName:SDLNameVRSynonyms];
 }
 
-- (NSArray<NSString *> *)vrSynonyms {
+- (nullable NSArray<NSString *> *)vrSynonyms {
     return [[parameters sdl_objectForName:SDLNameVRSynonyms] copy];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLChangeRegistrationResponse.h b/SmartDeviceLink/SDLChangeRegistrationResponse.h
index 20017d066..89c469fd9 100644
--- a/SmartDeviceLink/SDLChangeRegistrationResponse.h
+++ b/SmartDeviceLink/SDLChangeRegistrationResponse.h
@@ -9,6 +9,11 @@
  *
  * @since SDL 2.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLChangeRegistrationResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLChangeRegistrationResponse.m b/SmartDeviceLink/SDLChangeRegistrationResponse.m
index d17eb946e..1e5e6cbae 100644
--- a/SmartDeviceLink/SDLChangeRegistrationResponse.m
+++ b/SmartDeviceLink/SDLChangeRegistrationResponse.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLChangeRegistrationResponse
 
 - (instancetype)init {
@@ -16,3 +18,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLChoice.h b/SmartDeviceLink/SDLChoice.h
index b35deb299..1e88f097b 100644
--- a/SmartDeviceLink/SDLChoice.h
+++ b/SmartDeviceLink/SDLChoice.h
@@ -50,59 +50,63 @@
  *
  * Since <b>SmartDeviceLink 1.0</b><br>
  */
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLChoice : SDLRPCStruct
 
 - (instancetype)initWithId:(UInt16)choiceId menuName:(NSString *)menuName vrCommands:(NSArray<NSString *> *)vrCommands;
 
-- (instancetype)initWithId:(UInt16)choiceId menuName:(NSString *)menuName vrCommands:(NSArray<NSString *> *)vrCommands image:(SDLImage *)image secondaryText:(NSString *)secondaryText secondaryImage:(SDLImage *)secondaryImage tertiaryText:(NSString *)tertiaryText;
+- (instancetype)initWithId:(UInt16)choiceId menuName:(NSString *)menuName vrCommands:(NSArray<NSString *> *)vrCommands image:(nullable SDLImage *)image secondaryText:(nullable NSString *)secondaryText secondaryImage:(nullable SDLImage *)secondaryImage tertiaryText:(nullable NSString *)tertiaryText;
 
 /**
  * @abstract the application-scoped identifier that uniquely identifies this choice
  * 
  * Required, Integer 0 - 65535
  */
-@property (strong) NSNumber<SDLInt> *choiceID;
+@property (strong, nonatomic) NSNumber<SDLInt> *choiceID;
 
 /**
  * @abstract Text which appears in menu, representing this choice
  *
  * Required, Max string length 500 chars
  */
-@property (strong) NSString *menuName;
+@property (strong, nonatomic) NSString *menuName;
 
 /**
  * @abstract VR synonyms for this choice
  *
  * Required, Array of Strings, Array length 1 - 100, Max String length 99 chars
  */
-@property (strong) NSMutableArray<NSString *> *vrCommands;
+@property (strong, nonatomic) NSMutableArray<NSString *> *vrCommands;
 
 /**
  * @abstract The image of the choice
  *
  * Optional
  */
-@property (strong) SDLImage *image;
+@property (nullable, strong, nonatomic) SDLImage *image;
 
 /**
  * @abstract Optional secondary text to display; e.g. address of POI in a search result entry
  *
  * Optional, Max String length 500 chars
  */
-@property (strong) NSString *secondaryText;
+@property (nullable, strong, nonatomic) NSString *secondaryText;
 
 /**
  * @abstract Optional tertiary text to display; e.g. distance to POI for a search result entry
  *
  * Optional, Max String length 500 chars
  */
-@property (strong) NSString *tertiaryText;
+@property (nullable, strong, nonatomic) NSString *tertiaryText;
 
 /**
  * @abstract Optional secondary image for choice
  *
  * Optional
  */
-@property (strong) SDLImage *secondaryImage;
+@property (nullable, strong, nonatomic) SDLImage *secondaryImage;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLChoice.m b/SmartDeviceLink/SDLChoice.m
index ff712d830..b5fd077f5 100644
--- a/SmartDeviceLink/SDLChoice.m
+++ b/SmartDeviceLink/SDLChoice.m
@@ -7,9 +7,11 @@
 #import "SDLImage.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLChoice
 
-- (instancetype)initWithId:(UInt16)choiceId menuName:(NSString *)menuName vrCommands:(NSArray<NSString *> *)vrCommands image:(SDLImage *)image secondaryText:(NSString *)secondaryText secondaryImage:(SDLImage *)secondaryImage tertiaryText:(NSString *)tertiaryText {
+- (instancetype)initWithId:(UInt16)choiceId menuName:(NSString *)menuName vrCommands:(NSArray<NSString *> *)vrCommands image:(nullable SDLImage *)image secondaryText:(nullable NSString *)secondaryText secondaryImage:(nullable SDLImage *)secondaryImage tertiaryText:(nullable NSString *)tertiaryText {
     self = [self initWithId:choiceId menuName:menuName vrCommands:vrCommands];
     if (!self) {
         return nil;
@@ -60,36 +62,38 @@
     return [store sdl_objectForName:SDLNameVRCommands];
 }
 
-- (void)setImage:(SDLImage *)image {
+- (void)setImage:(nullable SDLImage *)image {
     [store sdl_setObject:image forName:SDLNameImage];
 }
 
-- (SDLImage *)image {
+- (nullable SDLImage *)image {
     return [store sdl_objectForName:SDLNameImage ofClass:SDLImage.class];
 }
 
-- (void)setSecondaryText:(NSString *)secondaryText {
+- (void)setSecondaryText:(nullable NSString *)secondaryText {
     [store sdl_setObject:secondaryText forName:SDLNameSecondaryText];
 }
 
-- (NSString *)secondaryText {
+- (nullable NSString *)secondaryText {
     return [store sdl_objectForName:SDLNameSecondaryText];
 }
 
-- (void)setTertiaryText:(NSString *)tertiaryText {
+- (void)setTertiaryText:(nullable NSString *)tertiaryText {
     [store sdl_setObject:tertiaryText forName:SDLNameTertiaryText];
 }
 
-- (NSString *)tertiaryText {
+- (nullable NSString *)tertiaryText {
     return [store sdl_objectForName:SDLNameTertiaryText];
 }
 
-- (void)setSecondaryImage:(SDLImage *)secondaryImage {
+- (void)setSecondaryImage:(nullable SDLImage *)secondaryImage {
     [store sdl_setObject:secondaryImage forName:SDLNameSecondaryImage];
 }
 
-- (SDLImage *)secondaryImage {
+- (nullable SDLImage *)secondaryImage {
     return [store sdl_objectForName:SDLNameSecondaryImage ofClass:SDLImage.class];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLClusterModeStatus.h b/SmartDeviceLink/SDLClusterModeStatus.h
index 5970fc69f..558a1fdcc 100644
--- a/SmartDeviceLink/SDLClusterModeStatus.h
+++ b/SmartDeviceLink/SDLClusterModeStatus.h
@@ -7,12 +7,15 @@
 #import "SDLPowerModeQualificationStatus.h"
 #import "SDLPowerModeStatus.h"
 
+NS_ASSUME_NONNULL_BEGIN
 
 @interface SDLClusterModeStatus : SDLRPCStruct
 
-@property (strong) NSNumber<SDLBool> *powerModeActive;
-@property (strong) SDLPowerModeQualificationStatus powerModeQualificationStatus;
-@property (strong) SDLCarModeStatus carModeStatus;
-@property (strong) SDLPowerModeStatus powerModeStatus;
+@property (strong, nonatomic) NSNumber<SDLBool> *powerModeActive;
+@property (strong, nonatomic) SDLPowerModeQualificationStatus powerModeQualificationStatus;
+@property (strong, nonatomic) SDLCarModeStatus carModeStatus;
+@property (strong, nonatomic) SDLPowerModeStatus powerModeStatus;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLClusterModeStatus.m b/SmartDeviceLink/SDLClusterModeStatus.m
index ba64af3de..e182fa17f 100644
--- a/SmartDeviceLink/SDLClusterModeStatus.m
+++ b/SmartDeviceLink/SDLClusterModeStatus.m
@@ -6,6 +6,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLClusterModeStatus
 
 - (void)setPowerModeActive:(NSNumber<SDLBool> *)powerModeActive {
@@ -41,3 +43,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLConsoleController.h b/SmartDeviceLink/SDLConsoleController.h
index 1376a2b5f..26cbd39cb 100644
--- a/SmartDeviceLink/SDLConsoleController.h
+++ b/SmartDeviceLink/SDLConsoleController.h
@@ -6,6 +6,7 @@
 
 #import "SDLDebugTool.h"
 
+NS_ASSUME_NONNULL_BEGIN
 
 @interface SDLConsoleController : UITableViewController <SDLDebugToolConsole> {
     NSMutableArray<NSDictionary<NSString *, id>*> *messageList;
@@ -13,9 +14,11 @@
     NSDateFormatter *dateFormatter;
 }
 
-@property (strong, readonly) NSMutableArray<NSDictionary<NSString *, id>*> *messageList;
+@property (strong, nonatomic, readonly) NSMutableArray<NSDictionary<NSString *, id>*> *messageList;
 
 - (instancetype)initWithTableView:(UITableView *)tableView;
 
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLCreateInteractionChoiceSet.h b/SmartDeviceLink/SDLCreateInteractionChoiceSet.h
index 2739c3c11..2679f0266 100644
--- a/SmartDeviceLink/SDLCreateInteractionChoiceSet.h
+++ b/SmartDeviceLink/SDLCreateInteractionChoiceSet.h
@@ -19,6 +19,8 @@
  *
  * @see SDLDeleteInteractionChoiceSet SDLPerformInteraction
  */
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLCreateInteractionChoiceSet : SDLRPCRequest
 
 - (instancetype)initWithId:(UInt32)choiceId choiceSet:(NSArray<SDLChoice *> *)choiceSet;
@@ -28,13 +30,15 @@
  *
  * Required, Integer, 0 - 2,000,000,000
  */
-@property (strong) NSNumber<SDLInt> *interactionChoiceSetID;
+@property (strong, nonatomic) NSNumber<SDLInt> *interactionChoiceSetID;
 
 /**
  * @abstract Array of choices, which the user can select by menu or voice recognition
  *
  * Required, SDLChoice, Array size 1 - 100
  */
-@property (strong) NSMutableArray<SDLChoice *> *choiceSet;
+@property (strong, nonatomic) NSMutableArray<SDLChoice *> *choiceSet;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLCreateInteractionChoiceSet.m b/SmartDeviceLink/SDLCreateInteractionChoiceSet.m
index 5a790e48d..f9e5ca73e 100644
--- a/SmartDeviceLink/SDLCreateInteractionChoiceSet.m
+++ b/SmartDeviceLink/SDLCreateInteractionChoiceSet.m
@@ -8,6 +8,8 @@
 #import "SDLChoice.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLCreateInteractionChoiceSet
 
 - (instancetype)init {
@@ -44,3 +46,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLCreateInteractionChoiceSetResponse.h b/SmartDeviceLink/SDLCreateInteractionChoiceSetResponse.h
index 0573dcc2f..0f9cd4346 100644
--- a/SmartDeviceLink/SDLCreateInteractionChoiceSetResponse.h
+++ b/SmartDeviceLink/SDLCreateInteractionChoiceSetResponse.h
@@ -10,6 +10,11 @@
  *
  * Since <b>SmartDeviceLink 1.0</b>
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLCreateInteractionChoiceSetResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLCreateInteractionChoiceSetResponse.m b/SmartDeviceLink/SDLCreateInteractionChoiceSetResponse.m
index 94b4860f5..b9de5f3b1 100644
--- a/SmartDeviceLink/SDLCreateInteractionChoiceSetResponse.m
+++ b/SmartDeviceLink/SDLCreateInteractionChoiceSetResponse.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLCreateInteractionChoiceSetResponse
 
 - (instancetype)init {
@@ -16,3 +18,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDIDResult.h b/SmartDeviceLink/SDLDIDResult.h
index 60eec5184..2ee14af44 100644
--- a/SmartDeviceLink/SDLDIDResult.h
+++ b/SmartDeviceLink/SDLDIDResult.h
@@ -5,11 +5,14 @@
 
 #import "SDLVehicleDataResultCode.h"
 
+NS_ASSUME_NONNULL_BEGIN
 
 @interface SDLDIDResult : SDLRPCStruct
 
-@property (strong) SDLVehicleDataResultCode resultCode;
-@property (strong) NSNumber<SDLInt> *didLocation;
-@property (strong) NSString *data;
+@property (strong, nonatomic) SDLVehicleDataResultCode resultCode;
+@property (strong, nonatomic) NSNumber<SDLInt> *didLocation;
+@property (nullable, strong, nonatomic) NSString *data;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDIDResult.m b/SmartDeviceLink/SDLDIDResult.m
index cc5dbb90a..0d0e5d39f 100644
--- a/SmartDeviceLink/SDLDIDResult.m
+++ b/SmartDeviceLink/SDLDIDResult.m
@@ -6,6 +6,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLDIDResult
 
 - (void)setResultCode:(SDLVehicleDataResultCode)resultCode {
@@ -24,12 +26,14 @@
     return [store sdl_objectForName:SDLNameDIDLocation];
 }
 
-- (void)setData:(NSString *)data {
+- (void)setData:(nullable NSString *)data {
     [store sdl_setObject:data forName:SDLNameData];
 }
 
-- (NSString *)data {
+- (nullable NSString *)data {
     return [store sdl_objectForName:SDLNameData];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDateTime.h b/SmartDeviceLink/SDLDateTime.h
index 7dffbd5d2..9239696c9 100644
--- a/SmartDeviceLink/SDLDateTime.h
+++ b/SmartDeviceLink/SDLDateTime.h
@@ -3,6 +3,8 @@
 
 #import "SDLRPCStruct.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLDateTime : SDLRPCStruct
 
 - (instancetype)initWithHour:(UInt8)hour minute:(UInt8)minute;
@@ -77,3 +79,5 @@
 @property (copy, nonatomic) NSNumber<SDLInt> *timezoneHourOffset;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDebugTool.h b/SmartDeviceLink/SDLDebugTool.h
index 98ddc6c77..9cb588edd 100644
--- a/SmartDeviceLink/SDLDebugTool.h
+++ b/SmartDeviceLink/SDLDebugTool.h
@@ -25,6 +25,8 @@ typedef NS_ENUM(UInt8, SDLDebugOutput) {
 };
 
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLDebugTool : NSObject {
 }
 
@@ -49,3 +51,5 @@ typedef NS_ENUM(UInt8, SDLDebugOutput) {
 
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDebugToolConsole.h b/SmartDeviceLink/SDLDebugToolConsole.h
index 75d541e16..941061851 100644
--- a/SmartDeviceLink/SDLDebugToolConsole.h
+++ b/SmartDeviceLink/SDLDebugToolConsole.h
@@ -4,9 +4,13 @@
 
 #import <Foundation/Foundation.h>
 
+NS_ASSUME_NONNULL_BEGIN
+
 @protocol SDLDebugToolConsole <NSObject>
 
 @required
 - (void)logInfo:(NSString *)info;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDeleteCommand.h b/SmartDeviceLink/SDLDeleteCommand.h
index ed2586d6d..2bc9e7769 100644
--- a/SmartDeviceLink/SDLDeleteCommand.h
+++ b/SmartDeviceLink/SDLDeleteCommand.h
@@ -16,6 +16,9 @@
  * Since <b>SmartDeviceLink 1.0</b><br>
  * see SDLAddCommand SDLAddSubMenu SDLDeleteSubMenu
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLDeleteCommand : SDLRPCRequest
 
 - (instancetype)initWithId:(UInt32)commandId;
@@ -26,6 +29,8 @@
  *            <p>
  *            <b>Notes: </b>Min Value: 0; Max Value: 2000000000
  */
-@property (strong) NSNumber<SDLInt> *cmdID;
+@property (strong, nonatomic) NSNumber<SDLInt> *cmdID;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDeleteCommand.m b/SmartDeviceLink/SDLDeleteCommand.m
index 1eb46f8de..d96276d56 100644
--- a/SmartDeviceLink/SDLDeleteCommand.m
+++ b/SmartDeviceLink/SDLDeleteCommand.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLDeleteCommand
 
 - (instancetype)init {
@@ -35,3 +37,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDeleteCommandResponse.h b/SmartDeviceLink/SDLDeleteCommandResponse.h
index 4c07a3c2f..95df39a6f 100644
--- a/SmartDeviceLink/SDLDeleteCommandResponse.h
+++ b/SmartDeviceLink/SDLDeleteCommandResponse.h
@@ -9,6 +9,11 @@
  *
  * Since <b>SmartDeviceLink 1.0</b><br>
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLDeleteCommandResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDeleteCommandResponse.m b/SmartDeviceLink/SDLDeleteCommandResponse.m
index f756c4ffe..f956c02ab 100644
--- a/SmartDeviceLink/SDLDeleteCommandResponse.m
+++ b/SmartDeviceLink/SDLDeleteCommandResponse.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLDeleteCommandResponse
 
 - (instancetype)init {
@@ -16,3 +18,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDeleteFile.h b/SmartDeviceLink/SDLDeleteFile.h
index 8c2188eeb..4372e4333 100644
--- a/SmartDeviceLink/SDLDeleteFile.h
+++ b/SmartDeviceLink/SDLDeleteFile.h
@@ -12,6 +12,9 @@
  * Since <b>SmartDeviceLink 2.0</b><br>
  * see SDLPutFile SDLListFiles
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLDeleteFile : SDLRPCRequest
 
 - (instancetype)initWithFileName:(NSString *)fileName;
@@ -20,6 +23,8 @@
  * @abstract a file reference name
  * @discussion a String value representing a file reference name
  */
-@property (strong) NSString *syncFileName;
+@property (strong, nonatomic) NSString *syncFileName;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDeleteFile.m b/SmartDeviceLink/SDLDeleteFile.m
index c66784ff9..b7a8929a2 100644
--- a/SmartDeviceLink/SDLDeleteFile.m
+++ b/SmartDeviceLink/SDLDeleteFile.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLDeleteFile
 
 - (instancetype)init {
@@ -35,3 +37,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDeleteFileResponse.h b/SmartDeviceLink/SDLDeleteFileResponse.h
index dc2a91f4d..aaf8e8f9e 100644
--- a/SmartDeviceLink/SDLDeleteFileResponse.h
+++ b/SmartDeviceLink/SDLDeleteFileResponse.h
@@ -9,8 +9,13 @@
  *
  * Since <b>SmartDeviceLink 2.0</b><br>
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLDeleteFileResponse : SDLRPCResponse
 
-@property (strong) NSNumber<SDLInt> *spaceAvailable;
+@property (strong, nonatomic) NSNumber<SDLInt> *spaceAvailable;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDeleteFileResponse.m b/SmartDeviceLink/SDLDeleteFileResponse.m
index c614e42e7..7065af0cf 100644
--- a/SmartDeviceLink/SDLDeleteFileResponse.m
+++ b/SmartDeviceLink/SDLDeleteFileResponse.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLDeleteFileResponse
 
 - (instancetype)init {
@@ -24,3 +26,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDeleteInteractionChoiceSet.h b/SmartDeviceLink/SDLDeleteInteractionChoiceSet.h
index 2504e633c..8c03f2eca 100644
--- a/SmartDeviceLink/SDLDeleteInteractionChoiceSet.h
+++ b/SmartDeviceLink/SDLDeleteInteractionChoiceSet.h
@@ -18,6 +18,9 @@
  * Since <b>SmartDeviceLink 1.0</b><br>
  * see SDLCreateInteractionChoiceSet SDLPerformInteraction
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLDeleteInteractionChoiceSet : SDLRPCRequest
 
 - (instancetype)initWithId:(UInt32)choiceId;
@@ -28,6 +31,8 @@
  * <p>
  * <b>Notes: </b>Min Value: 0; Max Value: 2000000000
  */
-@property (strong) NSNumber<SDLInt> *interactionChoiceSetID;
+@property (strong, nonatomic) NSNumber<SDLInt> *interactionChoiceSetID;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDeleteInteractionChoiceSet.m b/SmartDeviceLink/SDLDeleteInteractionChoiceSet.m
index 7816add86..a1f2585e5 100644
--- a/SmartDeviceLink/SDLDeleteInteractionChoiceSet.m
+++ b/SmartDeviceLink/SDLDeleteInteractionChoiceSet.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLDeleteInteractionChoiceSet
 
 - (instancetype)init {
@@ -35,3 +37,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDeleteInteractionChoiceSetResponse.h b/SmartDeviceLink/SDLDeleteInteractionChoiceSetResponse.h
index c67aef1d1..ad0dc0fc7 100644
--- a/SmartDeviceLink/SDLDeleteInteractionChoiceSetResponse.h
+++ b/SmartDeviceLink/SDLDeleteInteractionChoiceSetResponse.h
@@ -9,6 +9,11 @@
  *
  * Since <b>SmartDeviceLink 1.0</b>
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLDeleteInteractionChoiceSetResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDeleteInteractionChoiceSetResponse.m b/SmartDeviceLink/SDLDeleteInteractionChoiceSetResponse.m
index e8c2ba292..e6cc631fa 100644
--- a/SmartDeviceLink/SDLDeleteInteractionChoiceSetResponse.m
+++ b/SmartDeviceLink/SDLDeleteInteractionChoiceSetResponse.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLDeleteInteractionChoiceSetResponse
 
 - (instancetype)init {
@@ -16,3 +18,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDeleteSubMenu.h b/SmartDeviceLink/SDLDeleteSubMenu.h
index e1233f5c5..74a6363a9 100644
--- a/SmartDeviceLink/SDLDeleteSubMenu.h
+++ b/SmartDeviceLink/SDLDeleteSubMenu.h
@@ -16,6 +16,9 @@
  * Since <b>SmartDeviceLink 1.0</b><br>
  * see SDLAddCommand SDLAddSubMenu SDLDeleteCommand
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLDeleteSubMenu : SDLRPCRequest
 
 - (instancetype)initWithId:(UInt32)menuId;
@@ -24,6 +27,8 @@
  * @abstract the MenuID that identifies the SDLSubMenu to be delete
  * @discussion  <b>Notes: </b>Min Value: 0; Max Value: 2000000000
  */
-@property (strong) NSNumber<SDLInt> *menuID;
+@property (strong, nonatomic) NSNumber<SDLInt> *menuID;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDeleteSubMenu.m b/SmartDeviceLink/SDLDeleteSubMenu.m
index 1ce1b0f3f..b03372c7d 100644
--- a/SmartDeviceLink/SDLDeleteSubMenu.m
+++ b/SmartDeviceLink/SDLDeleteSubMenu.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLDeleteSubMenu
 
 - (instancetype)init {
@@ -35,3 +37,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDeleteSubMenuResponse.h b/SmartDeviceLink/SDLDeleteSubMenuResponse.h
index 5842a54be..e50781e85 100644
--- a/SmartDeviceLink/SDLDeleteSubMenuResponse.h
+++ b/SmartDeviceLink/SDLDeleteSubMenuResponse.h
@@ -9,6 +9,11 @@
  *
  * Since <b>SmartDeviceLink 1.0</b>
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLDeleteSubMenuResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDeleteSubMenuResponse.m b/SmartDeviceLink/SDLDeleteSubMenuResponse.m
index 0ef3c4f77..5594763e9 100644
--- a/SmartDeviceLink/SDLDeleteSubMenuResponse.m
+++ b/SmartDeviceLink/SDLDeleteSubMenuResponse.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLDeleteSubMenuResponse
 
 - (instancetype)init {
@@ -16,3 +18,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDeviceInfo.h b/SmartDeviceLink/SDLDeviceInfo.h
index 1e34434a0..0af061abc 100644
--- a/SmartDeviceLink/SDLDeviceInfo.h
+++ b/SmartDeviceLink/SDLDeviceInfo.h
@@ -3,16 +3,19 @@
 
 #import "SDLRPCMessage.h"
 
+NS_ASSUME_NONNULL_BEGIN
 
 @interface SDLDeviceInfo : SDLRPCStruct
 
 + (instancetype)currentDevice;
 
-@property (strong) NSString *hardware;
-@property (strong) NSString *firmwareRev;
-@property (strong) NSString *os;
-@property (strong) NSString *osVersion;
-@property (strong) NSString *carrier;
-@property (strong) NSNumber<SDLInt> *maxNumberRFCOMMPorts;
+@property (nullable, strong, nonatomic) NSString *hardware;
+@property (nullable, strong, nonatomic) NSString *firmwareRev;
+@property (nullable, strong, nonatomic) NSString *os;
+@property (nullable, strong, nonatomic) NSString *osVersion;
+@property (nullable, strong, nonatomic) NSString *carrier;
+@property (nullable, strong, nonatomic) NSNumber<SDLInt> *maxNumberRFCOMMPorts;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDeviceInfo.m b/SmartDeviceLink/SDLDeviceInfo.m
index 6638eff3c..8b321bf8d 100644
--- a/SmartDeviceLink/SDLDeviceInfo.m
+++ b/SmartDeviceLink/SDLDeviceInfo.m
@@ -10,6 +10,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLDeviceInfo
 
 + (instancetype)currentDevice {
@@ -27,52 +29,54 @@
     return deviceInfo;
 }
 
-- (void)setHardware:(NSString *)hardware {
+- (void)setHardware:(nullable NSString *)hardware {
     [store sdl_setObject:hardware forName:SDLNameHardware];
 }
 
-- (NSString *)hardware {
+- (nullable NSString *)hardware {
     return [store sdl_objectForName:SDLNameHardware];
 }
 
-- (void)setFirmwareRev:(NSString *)firmwareRev {
+- (void)setFirmwareRev:(nullable NSString *)firmwareRev {
     [store sdl_setObject:firmwareRev forName:SDLNameFirmwareRevision];
 }
 
-- (NSString *)firmwareRev {
+- (nullable NSString *)firmwareRev {
     return [store sdl_objectForName:SDLNameFirmwareRevision];
 }
 
-- (void)setOs:(NSString *)os {
+- (void)setOs:(nullable NSString *)os {
     [store sdl_setObject:os forName:SDLNameOS];
 }
 
-- (NSString *)os {
+- (nullable NSString *)os {
     return [store sdl_objectForName:SDLNameOS];
 }
 
-- (void)setOsVersion:(NSString *)osVersion {
+- (void)setOsVersion:(nullable NSString *)osVersion {
     [store sdl_setObject:osVersion forName:SDLNameOSVersion];
 }
 
-- (NSString *)osVersion {
+- (nullable NSString *)osVersion {
     return [store sdl_objectForName:SDLNameOSVersion];
 }
 
-- (void)setCarrier:(NSString *)carrier {
+- (void)setCarrier:(nullable NSString *)carrier {
     [store sdl_setObject:carrier forName:SDLNameCarrier];
 }
 
-- (NSString *)carrier {
+- (nullable NSString *)carrier {
     return [store sdl_objectForName:SDLNameCarrier];
 }
 
-- (void)setMaxNumberRFCOMMPorts:(NSNumber<SDLInt> *)maxNumberRFCOMMPorts {
+- (void)setMaxNumberRFCOMMPorts:(nullable NSNumber<SDLInt> *)maxNumberRFCOMMPorts {
     [store sdl_setObject:maxNumberRFCOMMPorts forName:SDLNameMaxNumberRFCOMMPorts];
 }
 
-- (NSNumber<SDLInt> *)maxNumberRFCOMMPorts {
+- (nullable NSNumber<SDLInt> *)maxNumberRFCOMMPorts {
     return [store sdl_objectForName:SDLNameMaxNumberRFCOMMPorts];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDeviceStatus.h b/SmartDeviceLink/SDLDeviceStatus.h
index 0a81176e3..d1f36d215 100644
--- a/SmartDeviceLink/SDLDeviceStatus.h
+++ b/SmartDeviceLink/SDLDeviceStatus.h
@@ -98,6 +98,9 @@
  *  </table>
  * @since SDL 2.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLDeviceStatus : SDLRPCStruct
 
 /**
@@ -105,35 +108,35 @@
  *
  * Required, Boolean
  */
-@property (strong) NSNumber<SDLBool> *voiceRecOn;
+@property (strong, nonatomic) NSNumber<SDLBool> *voiceRecOn;
 
 /**
  * @abstract Indicates whether the bluetooth connection established
  *
  * Required, Boolean
  */
-@property (strong) NSNumber<SDLBool> *btIconOn;
+@property (strong, nonatomic) NSNumber<SDLBool> *btIconOn;
 
 /**
  * @abstract Indicates whether a call is being active
  *
  * Required, Boolean
  */
-@property (strong) NSNumber<SDLBool> *callActive;
+@property (strong, nonatomic) NSNumber<SDLBool> *callActive;
 
 /**
  * @abstract Indicates whether the phone is in roaming mode
  *
  * Required, Boolean
  */
-@property (strong) NSNumber<SDLBool> *phoneRoaming;
+@property (strong, nonatomic) NSNumber<SDLBool> *phoneRoaming;
 
 /**
  * @abstract Indicates whether a textmessage is available
  *
  * Required, Boolean
  */
-@property (strong) NSNumber<SDLBool> *textMsgAvailable;
+@property (strong, nonatomic) NSNumber<SDLBool> *textMsgAvailable;
 
 /**
  * @abstract Battery level status
@@ -142,21 +145,21 @@
  *
  * Required
  */
-@property (strong) SDLDeviceLevelStatus battLevelStatus;
+@property (strong, nonatomic) SDLDeviceLevelStatus battLevelStatus;
 
 /**
  * @abstract The status of the stereo audio output channel
  *
  * Required, Boolean
  */
-@property (strong) NSNumber<SDLBool> *stereoAudioOutputMuted;
+@property (strong, nonatomic) NSNumber<SDLBool> *stereoAudioOutputMuted;
 
 /**
  * @abstract The status of the mono audio output channel
  *
  * Required, Boolean
  */
-@property (strong) NSNumber<SDLBool> *monoAudioOutputMuted;
+@property (strong, nonatomic) NSNumber<SDLBool> *monoAudioOutputMuted;
 
 /**
  * @abstract Signal level status
@@ -165,7 +168,7 @@
  *
  * Required
  */
-@property (strong) SDLDeviceLevelStatus signalLevelStatus;
+@property (strong, nonatomic) SDLDeviceLevelStatus signalLevelStatus;
 
 /**
  * @abstract The current primary audio source of SDL (if selected).
@@ -174,13 +177,15 @@
  * 
  * Required
  */
-@property (strong) SDLPrimaryAudioSource primaryAudioSource;
+@property (strong, nonatomic) SDLPrimaryAudioSource primaryAudioSource;
 
 /**
  * @abstract Indicates if an emergency call is active
  *
  * Required, Boolean
  */
-@property (strong) NSNumber<SDLBool> *eCallEventActive;
+@property (strong, nonatomic) NSNumber<SDLBool> *eCallEventActive;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDeviceStatus.m b/SmartDeviceLink/SDLDeviceStatus.m
index 8015d568a..ca449c517 100644
--- a/SmartDeviceLink/SDLDeviceStatus.m
+++ b/SmartDeviceLink/SDLDeviceStatus.m
@@ -8,6 +8,8 @@
 #import "SDLNames.h"
 #import "SDLPrimaryAudioSource.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLDeviceStatus
 
 - (void)setVoiceRecOn:(NSNumber<SDLBool> *)voiceRecOn {
@@ -99,3 +101,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDiagnosticMessage.h b/SmartDeviceLink/SDLDiagnosticMessage.h
index 3070a5684..e5bff4a58 100644
--- a/SmartDeviceLink/SDLDiagnosticMessage.h
+++ b/SmartDeviceLink/SDLDiagnosticMessage.h
@@ -9,6 +9,9 @@
  *
  * @since SDL 3.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLDiagnosticMessage : SDLRPCRequest
 
 - (instancetype)initWithTargetId:(UInt16)targetId length:(UInt16)length data:(NSArray<NSNumber<SDLUInt> *> *)data;
@@ -18,20 +21,22 @@
  *
  * Required, Integer, 0 - 65535
  */
-@property (strong) NSNumber<SDLInt> *targetID;
+@property (strong, nonatomic) NSNumber<SDLInt> *targetID;
 
 /**
  * Length of message (in bytes)
  *
  * Required, Integer, 65535
  */
-@property (strong) NSNumber<SDLInt> *messageLength;
+@property (strong, nonatomic) NSNumber<SDLInt> *messageLength;
 
 /**
  *  Array of bytes comprising CAN message.
  *
  * Required, Array of NSNumber (Integers), Array size 1 - 65535, Integer Size 0 - 255
  */
-@property (strong) NSMutableArray<NSNumber<SDLInt> *> *messageData;
+@property (strong, nonatomic) NSMutableArray<NSNumber<SDLInt> *> *messageData;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDiagnosticMessage.m b/SmartDeviceLink/SDLDiagnosticMessage.m
index 69bcee0d1..4b874a6e2 100644
--- a/SmartDeviceLink/SDLDiagnosticMessage.m
+++ b/SmartDeviceLink/SDLDiagnosticMessage.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLDiagnosticMessage
 
 - (instancetype)init {
@@ -53,3 +55,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDiagnosticMessageResponse.h b/SmartDeviceLink/SDLDiagnosticMessageResponse.h
index 7021a91ed..5c4c8745f 100644
--- a/SmartDeviceLink/SDLDiagnosticMessageResponse.h
+++ b/SmartDeviceLink/SDLDiagnosticMessageResponse.h
@@ -7,8 +7,13 @@
 /** SDLDiagnosticMessageResponse is sent, when SDLDiagnosticMessage has been called.
  * Since<b>SmartDeviceLink 3.0</b>
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLDiagnosticMessageResponse : SDLRPCResponse
 
-@property (strong) NSMutableArray<NSNumber<SDLInt> *> *messageDataResult;
+@property (strong, nonatomic) NSMutableArray<NSNumber<SDLInt> *> *messageDataResult;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDiagnosticMessageResponse.m b/SmartDeviceLink/SDLDiagnosticMessageResponse.m
index 09d05625c..9353a755f 100644
--- a/SmartDeviceLink/SDLDiagnosticMessageResponse.m
+++ b/SmartDeviceLink/SDLDiagnosticMessageResponse.m
@@ -6,6 +6,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLDiagnosticMessageResponse
 
 - (instancetype)init {
@@ -23,3 +25,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDialNumber.h b/SmartDeviceLink/SDLDialNumber.h
index a2b3bc474..292ab7adc 100644
--- a/SmartDeviceLink/SDLDialNumber.h
+++ b/SmartDeviceLink/SDLDialNumber.h
@@ -9,6 +9,9 @@
  
  @since SDL 4.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLDialNumber : SDLRPCRequest
 
 - (instancetype)initWithNumber:(NSString *)number;
@@ -19,3 +22,5 @@
 @property (strong, nonatomic) NSString *number;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDialNumberResponse.h b/SmartDeviceLink/SDLDialNumberResponse.h
index 1270751ac..7f8dfaa14 100644
--- a/SmartDeviceLink/SDLDialNumberResponse.h
+++ b/SmartDeviceLink/SDLDialNumberResponse.h
@@ -9,6 +9,11 @@
  
  @since SDL 4.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLDialNumberResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDialNumberResponse.m b/SmartDeviceLink/SDLDialNumberResponse.m
index 2d38855b0..b791e2cd2 100644
--- a/SmartDeviceLink/SDLDialNumberResponse.m
+++ b/SmartDeviceLink/SDLDialNumberResponse.m
@@ -7,6 +7,7 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
 
 @implementation SDLDialNumberResponse
 
@@ -17,3 +18,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDisplayCapabilities.h b/SmartDeviceLink/SDLDisplayCapabilities.h
index 0e12ff682..437f686fc 100644
--- a/SmartDeviceLink/SDLDisplayCapabilities.h
+++ b/SmartDeviceLink/SDLDisplayCapabilities.h
@@ -15,6 +15,9 @@
  * 
  * @since SDL 1.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLDisplayCapabilities : SDLRPCStruct
 
 /**
@@ -22,7 +25,7 @@
  *
  * Required
  */
-@property (strong) SDLDisplayType displayType;
+@property (strong, nonatomic) SDLDisplayType displayType;
 
 /**
  * @abstract An array of SDLTextField structures, each of which describes a field in the HMI which the application can write to using operations such as *SDLShow*, *SDLSetMediaClockTimer*, etc.
@@ -33,7 +36,7 @@
  *
  * Required, Array of SDLTextField, 1 - 100 objects
  */
-@property (strong) NSMutableArray<SDLTextField *> *textFields;
+@property (strong, nonatomic) NSMutableArray<SDLTextField *> *textFields;
 
 /**
  * @abstract An array of SDLImageField elements
@@ -44,7 +47,7 @@
  *
  * Optional, Array of SDLImageField, 1 - 100 objects
  */
-@property (strong) NSMutableArray<SDLImageField *> *imageFields;
+@property (nullable, strong, nonatomic) NSMutableArray<SDLImageField *> *imageFields;
 
 /**
  * @abstract An array of SDLMediaClockFormat elements, defining the valid string formats used in specifying the contents of the media clock field
@@ -53,7 +56,7 @@
  *
  * Required, Array of SDLMediaClockFormats, 0 - 100 objects
  */
-@property (strong) NSMutableArray<SDLMediaClockFormat> *mediaClockFormats;
+@property (strong, nonatomic) NSMutableArray<SDLMediaClockFormat> *mediaClockFormats;
 
 /**
  * @abstract The display's persistent screen supports.
@@ -62,7 +65,7 @@
  *
  * Required, Boolean
  */
-@property (strong) NSNumber<SDLBool> *graphicSupported;
+@property (strong, nonatomic) NSNumber<SDLBool> *graphicSupported;
 
 /**
  * @abstract Number of presets the screen supports
@@ -71,20 +74,22 @@
  *
  * Optional, Array of String, max string size 100, 0 - 100 objects
  */
-@property (strong) NSMutableArray<NSString *> *templatesAvailable;
+@property (nullable, strong, nonatomic) NSMutableArray<NSString *> *templatesAvailable;
 
 /**
  * @abstract A set of all parameters related to a prescribed screen area (e.g. for video / touch input)
  *
  * Optional
  */
-@property (strong) SDLScreenParams *screenParams;
+@property (nullable, strong, nonatomic) SDLScreenParams *screenParams;
 
 /**
  * @abstract The number of on-screen custom presets available (if any); otherwise omitted
  *
  * Optional, Integer 1 - 100
  */
-@property (strong) NSNumber<SDLInt> *numCustomPresetsAvailable;
+@property (nullable, strong, nonatomic) NSNumber<SDLInt> *numCustomPresetsAvailable;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLDisplayCapabilities.m b/SmartDeviceLink/SDLDisplayCapabilities.m
index de9479594..dc3e45c5f 100644
--- a/SmartDeviceLink/SDLDisplayCapabilities.m
+++ b/SmartDeviceLink/SDLDisplayCapabilities.m
@@ -9,6 +9,8 @@
 #import "SDLScreenParams.h"
 #import "SDLTextField.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLDisplayCapabilities
 
 - (void)setDisplayType:(SDLDisplayType)displayType {
@@ -27,11 +29,11 @@
     return [store sdl_objectsForName:SDLNameTextFields ofClass:SDLTextField.class];
 }
 
-- (void)setImageFields:(NSMutableArray<SDLImageField *> *)imageFields {
+- (void)setImageFields:(nullable NSMutableArray<SDLImageField *> *)imageFields {
     [store sdl_setObject:imageFields forName:SDLNameImageFields];
 }
 
-- (NSMutableArray<SDLImageField *> *)imageFields {
+- (nullable NSMutableArray<SDLImageField *> *)imageFields {
     return [store sdl_objectsForName:SDLNameImageFields ofClass:SDLImageField.class];
 }
 
@@ -51,28 +53,30 @@
     return [store sdl_objectForName:SDLNameGraphicSupported];
 }
 
-- (void)setTemplatesAvailable:(NSMutableArray<NSString *> *)templatesAvailable {
+- (void)setTemplatesAvailable:(nullable NSMutableArray<NSString *> *)templatesAvailable {
     [store sdl_setObject:templatesAvailable forName:SDLNameTemplatesAvailable];
 }
 
-- (NSMutableArray<NSString *> *)templatesAvailable {
+- (nullable NSMutableArray<NSString *> *)templatesAvailable {
     return [store sdl_objectForName:SDLNameTemplatesAvailable];
 }
 
-- (void)setScreenParams:(SDLScreenParams *)screenParams {
+- (void)setScreenParams:(nullable SDLScreenParams *)screenParams {
     [store sdl_setObject:screenParams forName:SDLNameScreenParams];
 }
 
-- (SDLScreenParams *)screenParams {
+- (nullable SDLScreenParams *)screenParams {
     return [store sdl_objectForName:SDLNameScreenParams ofClass:SDLScreenParams.class];
 }
 
-- (void)setNumCustomPresetsAvailable:(NSNumber<SDLInt> *)numCustomPresetsAvailable {
+- (void)setNumCustomPresetsAvailable:(nullable NSNumber<SDLInt> *)numCustomPresetsAvailable {
     [store sdl_setObject:numCustomPresetsAvailable forName:SDLNameNumberCustomPresetsAvailable];
 }
 
-- (NSNumber<SDLInt> *)numCustomPresetsAvailable {
+- (nullable NSNumber<SDLInt> *)numCustomPresetsAvailable {
     return [store sdl_objectForName:SDLNameNumberCustomPresetsAvailable];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLECallInfo.h b/SmartDeviceLink/SDLECallInfo.h
index d0443d3dd..75d88f309 100644
--- a/SmartDeviceLink/SDLECallInfo.h
+++ b/SmartDeviceLink/SDLECallInfo.h
@@ -6,11 +6,14 @@
 #import "SDLECallConfirmationStatus.h"
 #import "SDLVehicleDataNotificationStatus.h"
 
+NS_ASSUME_NONNULL_BEGIN
 
 @interface SDLECallInfo : SDLRPCStruct
 
-@property (strong) SDLVehicleDataNotificationStatus eCallNotificationStatus;
-@property (strong) SDLVehicleDataNotificationStatus auxECallNotificationStatus;
-@property (strong) SDLECallConfirmationStatus eCallConfirmationStatus;
+@property (strong, nonatomic) SDLVehicleDataNotificationStatus eCallNotificationStatus;
+@property (strong, nonatomic) SDLVehicleDataNotificationStatus auxECallNotificationStatus;
+@property (strong, nonatomic) SDLECallConfirmationStatus eCallConfirmationStatus;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLECallInfo.m b/SmartDeviceLink/SDLECallInfo.m
index 2ec37c1a8..656ee3329 100644
--- a/SmartDeviceLink/SDLECallInfo.m
+++ b/SmartDeviceLink/SDLECallInfo.m
@@ -6,6 +6,7 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
 
 @implementation SDLECallInfo
 
@@ -34,3 +35,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLEmergencyEvent.h b/SmartDeviceLink/SDLEmergencyEvent.h
index 4fbf15a44..759c64659 100644
--- a/SmartDeviceLink/SDLEmergencyEvent.h
+++ b/SmartDeviceLink/SDLEmergencyEvent.h
@@ -7,13 +7,16 @@
 #import "SDLFuelCutoffStatus.h"
 #import "SDLVehicleDataEventStatus.h"
 
+NS_ASSUME_NONNULL_BEGIN
 
 @interface SDLEmergencyEvent : SDLRPCStruct
 
-@property (strong) SDLEmergencyEventType emergencyEventType;
-@property (strong) SDLFuelCutoffStatus fuelCutoffStatus;
-@property (strong) SDLVehicleDataEventStatus rolloverEvent;
-@property (strong) NSNumber<SDLInt> *maximumChangeVelocity;
-@property (strong) SDLVehicleDataEventStatus multipleEvents;
+@property (strong, nonatomic) SDLEmergencyEventType emergencyEventType;
+@property (strong, nonatomic) SDLFuelCutoffStatus fuelCutoffStatus;
+@property (strong, nonatomic) SDLVehicleDataEventStatus rolloverEvent;
+@property (strong, nonatomic) NSNumber<SDLInt> *maximumChangeVelocity;
+@property (strong, nonatomic) SDLVehicleDataEventStatus multipleEvents;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLEmergencyEvent.m b/SmartDeviceLink/SDLEmergencyEvent.m
index 8214503b2..1aa18743e 100644
--- a/SmartDeviceLink/SDLEmergencyEvent.m
+++ b/SmartDeviceLink/SDLEmergencyEvent.m
@@ -6,6 +6,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLEmergencyEvent
 
 - (void)setEmergencyEventType:(SDLEmergencyEventType)emergencyEventType {
@@ -49,3 +51,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLEncodedSyncPData.h b/SmartDeviceLink/SDLEncodedSyncPData.h
index 65f5038f8..5d32ced74 100644
--- a/SmartDeviceLink/SDLEncodedSyncPData.h
+++ b/SmartDeviceLink/SDLEncodedSyncPData.h
@@ -4,8 +4,12 @@
 
 #import "SDLRPCRequest.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLEncodedSyncPData : SDLRPCRequest
 
-@property (strong) NSMutableArray<NSString *> *data;
+@property (strong, nonatomic) NSMutableArray<NSString *> *data;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLEncodedSyncPData.m b/SmartDeviceLink/SDLEncodedSyncPData.m
index 063b7d441..39873052f 100644
--- a/SmartDeviceLink/SDLEncodedSyncPData.m
+++ b/SmartDeviceLink/SDLEncodedSyncPData.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLEncodedSyncPData
 
 - (instancetype)init {
@@ -24,3 +26,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLEncodedSyncPDataResponse.h b/SmartDeviceLink/SDLEncodedSyncPDataResponse.h
index ff1dec1ac..f8a4daf20 100644
--- a/SmartDeviceLink/SDLEncodedSyncPDataResponse.h
+++ b/SmartDeviceLink/SDLEncodedSyncPDataResponse.h
@@ -4,6 +4,10 @@
 
 #import "SDLRPCResponse.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLEncodedSyncPDataResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLEncodedSyncPDataResponse.m b/SmartDeviceLink/SDLEncodedSyncPDataResponse.m
index 4bbc652d3..c8d4c673e 100644
--- a/SmartDeviceLink/SDLEncodedSyncPDataResponse.m
+++ b/SmartDeviceLink/SDLEncodedSyncPDataResponse.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLEncodedSyncPDataResponse
 
 - (instancetype)init {
@@ -16,3 +18,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLEndAudioPassThru.h b/SmartDeviceLink/SDLEndAudioPassThru.h
index 6c5d82914..f3c87e0f1 100644
--- a/SmartDeviceLink/SDLEndAudioPassThru.h
+++ b/SmartDeviceLink/SDLEndAudioPassThru.h
@@ -14,6 +14,11 @@
  * Since <b>SmartDeviceLink 2.0</b><br>
  * see SDLPerformAudioPassThru
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLEndAudioPassThru : SDLRPCRequest
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLEndAudioPassThru.m b/SmartDeviceLink/SDLEndAudioPassThru.m
index 0203eba21..127702a06 100644
--- a/SmartDeviceLink/SDLEndAudioPassThru.m
+++ b/SmartDeviceLink/SDLEndAudioPassThru.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLEndAudioPassThru
 
 - (instancetype)init {
@@ -16,3 +18,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLEndAudioPassThruResponse.h b/SmartDeviceLink/SDLEndAudioPassThruResponse.h
index 1e976a6f8..bda7b4f89 100644
--- a/SmartDeviceLink/SDLEndAudioPassThruResponse.h
+++ b/SmartDeviceLink/SDLEndAudioPassThruResponse.h
@@ -9,6 +9,11 @@
  *
  * Since <b>SmartDeviceLink 2.0</b>
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLEndAudioPassThruResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLEndAudioPassThruResponse.m b/SmartDeviceLink/SDLEndAudioPassThruResponse.m
index 636d4cf87..3efaa3915 100644
--- a/SmartDeviceLink/SDLEndAudioPassThruResponse.m
+++ b/SmartDeviceLink/SDLEndAudioPassThruResponse.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLEndAudioPassThruResponse
 
 - (instancetype)init {
@@ -16,3 +18,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLFunctionID.h b/SmartDeviceLink/SDLFunctionID.h
index f50eb01f7..7cb9d6cb1 100644
--- a/SmartDeviceLink/SDLFunctionID.h
+++ b/SmartDeviceLink/SDLFunctionID.h
@@ -8,11 +8,15 @@
 #import "SDLNames.h"
 #import "NSNumber+NumberType.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLFunctionID : NSObject
 
 + (instancetype)sharedInstance;
 
-- (SDLName)functionNameForId:(int)functionID;
-- (NSNumber<SDLInt> *)functionIdForName:(SDLName)functionName;
+- (nullable SDLName)functionNameForId:(int)functionID;
+- (nullable NSNumber<SDLInt> *)functionIdForName:(SDLName)functionName;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLFunctionID.m b/SmartDeviceLink/SDLFunctionID.m
index 18caf940e..17c6ba822 100644
--- a/SmartDeviceLink/SDLFunctionID.m
+++ b/SmartDeviceLink/SDLFunctionID.m
@@ -4,6 +4,8 @@
 
 #import "SDLFunctionID.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLFunctionID ()
 
 @property (nonatomic, strong, nonnull) NSDictionary* functionIds;
@@ -93,14 +95,16 @@
     return self;
 }
 
-- (SDLName)functionNameForId:(int)functionID {
+- (nullable SDLName)functionNameForId:(int)functionID {
     return self.functionIds[@(functionID)];
 }
 
 
-- (NSNumber<SDLInt> *)functionIdForName:(SDLName)functionName {
+- (nullable NSNumber<SDLInt> *)functionIdForName:(SDLName)functionName {
     return [[self.functionIds allKeysForObject:functionName] firstObject];
 }
 
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLGPSData.h b/SmartDeviceLink/SDLGPSData.h
index 8a1a9a5d1..892bd7e46 100644
--- a/SmartDeviceLink/SDLGPSData.h
+++ b/SmartDeviceLink/SDLGPSData.h
@@ -12,6 +12,9 @@
  * 
  * @since SDL 2.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLGPSData : SDLRPCStruct
 
 /**
@@ -19,61 +22,61 @@
  *
  * Required, Float, -180 - 180
  */
-@property (strong) NSNumber<SDLFloat> *longitudeDegrees;
+@property (strong, nonatomic) NSNumber<SDLFloat> *longitudeDegrees;
 
 /**
  * @abstract latitude degrees
  *
  * Required, Float, -90 - 90
  */
-@property (strong) NSNumber<SDLFloat> *latitudeDegrees;
+@property (strong, nonatomic) NSNumber<SDLFloat> *latitudeDegrees;
 
 /**
  * @abstract utc year
  *
  * Required, Integer, 2010 - 2100
  */
-@property (strong) NSNumber<SDLInt> *utcYear;
+@property (strong, nonatomic) NSNumber<SDLInt> *utcYear;
 
 /**
  * @abstract utc month
  *
  * Required, Integer, 1 - 12
  */
-@property (strong) NSNumber<SDLInt> *utcMonth;
+@property (strong, nonatomic) NSNumber<SDLInt> *utcMonth;
 
 /**
  * @abstract utc day
  *
  * Required, Integer, 1 - 31
  */
-@property (strong) NSNumber<SDLInt> *utcDay;
+@property (strong, nonatomic) NSNumber<SDLInt> *utcDay;
 
 /**
  * @abstract utc hours
  *
  * Required, Integer, 0 - 23
  */
-@property (strong) NSNumber<SDLInt> *utcHours;
+@property (strong, nonatomic) NSNumber<SDLInt> *utcHours;
 
 /**
  * @abstract utc minutes
  *
  * Required, Integer, 0 - 59
  */
-@property (strong) NSNumber<SDLInt> *utcMinutes;
+@property (strong, nonatomic) NSNumber<SDLInt> *utcMinutes;
 
 /**
  * @abstract utc seconds
  *
  * Required, Integer, 0 - 59
  */
-@property (strong) NSNumber<SDLInt> *utcSeconds;
+@property (strong, nonatomic) NSNumber<SDLInt> *utcSeconds;
 
 /**
  * Potential Compass Directions
  */
-@property (strong) SDLCompassDirection compassDirection;
+@property (strong, nonatomic) SDLCompassDirection compassDirection;
 
 /**
  * @abstract The 3D positional dilution of precision.
@@ -82,7 +85,7 @@
  *
  * Required, Float, 0.0 - 10.0
  */
-@property (strong) NSNumber<SDLFloat> *pdop;
+@property (strong, nonatomic) NSNumber<SDLFloat> *pdop;
 
 /**
  * @abstract The horizontal dilution of precision
@@ -91,7 +94,7 @@
  *
  * Required, Float, 0.0 - 10.0
  */
-@property (strong) NSNumber<SDLFloat> *hdop;
+@property (strong, nonatomic) NSNumber<SDLFloat> *hdop;
 
 /**
  * @abstract the vertical dilution of precision
@@ -100,7 +103,7 @@
  *
  * Required, Float, 0.0 - 10.0
  */
-@property (strong) NSNumber<SDLFloat> *vdop;
+@property (strong, nonatomic) NSNumber<SDLFloat> *vdop;
 
 /**
  * @abstract What the coordinates are based on
@@ -109,28 +112,28 @@
  *
  * Required, Boolean
  */
-@property (strong) NSNumber<SDLBool> *actual;
+@property (strong, nonatomic) NSNumber<SDLBool> *actual;
 
 /**
  * @abstract The number of satellites in view
  *
  * Required, Integer, 0 - 31
  */
-@property (strong) NSNumber<SDLInt> *satellites;
+@property (strong, nonatomic) NSNumber<SDLInt> *satellites;
 
 /**
  * The supported dimensions of the GPS
  *
  * Required
  */
-@property (strong) SDLDimension dimension;
+@property (strong, nonatomic) SDLDimension dimension;
 
 /**
  * @abstract altitude in meters
  *
  * Required, Float, -10000.0 - 10000.0
  */
-@property (strong) NSNumber<SDLFloat> *altitude;
+@property (strong, nonatomic) NSNumber<SDLFloat> *altitude;
 
 /**
  * @abstract Heading based on the GPS data.
@@ -139,13 +142,15 @@
  *
  * Required, Float, 0.0 - 359.99
  */
-@property (strong) NSNumber<SDLFloat> *heading;
+@property (strong, nonatomic) NSNumber<SDLFloat> *heading;
 
 /**
  * @abstract speed in KPH
  *
  * Required, Float, 0.0 - 500.0
  */
-@property (strong) NSNumber<SDLFloat> *speed;
+@property (strong, nonatomic) NSNumber<SDLFloat> *speed;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLGPSData.m b/SmartDeviceLink/SDLGPSData.m
index 9096d9d46..8bd17706f 100644
--- a/SmartDeviceLink/SDLGPSData.m
+++ b/SmartDeviceLink/SDLGPSData.m
@@ -6,6 +6,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLGPSData
 
 - (void)setLongitudeDegrees:(NSNumber<SDLFloat> *)longitudeDegrees {
@@ -153,3 +155,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLGenericResponse.h b/SmartDeviceLink/SDLGenericResponse.h
index 61e1f2c8d..74f1fa495 100644
--- a/SmartDeviceLink/SDLGenericResponse.h
+++ b/SmartDeviceLink/SDLGenericResponse.h
@@ -9,6 +9,11 @@
  * retrieved. Only used in case of an error. Currently, only resultCode
  * INVALID_DATA is used.
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLGenericResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLGenericResponse.m b/SmartDeviceLink/SDLGenericResponse.m
index a4d937950..6c3849018 100644
--- a/SmartDeviceLink/SDLGenericResponse.m
+++ b/SmartDeviceLink/SDLGenericResponse.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLGenericResponse
 
 - (instancetype)init {
@@ -16,3 +18,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLGetDTCs.h b/SmartDeviceLink/SDLGetDTCs.h
index 6d60747ed..c212e7f95 100644
--- a/SmartDeviceLink/SDLGetDTCs.h
+++ b/SmartDeviceLink/SDLGetDTCs.h
@@ -13,6 +13,9 @@
  * <b>HMILevel needs to be FULL, LIMITED or BACKGROUND</b>
  * <p>
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLGetDTCs : SDLRPCRequest
 
 - (instancetype)initWithECUName:(UInt16)name;
@@ -26,9 +29,11 @@
  *            <p>
  *            <b>Notes: </b>Minvalue:0; Maxvalue:65535
  */
-@property (strong) NSNumber<SDLInt> *ecuName;
+@property (strong, nonatomic) NSNumber<SDLInt> *ecuName;
 /**
  * @abstract  DTC Mask Byte to be sent in diagnostic request to module. NSNumber* dtcMask Minvalue:0; Maxvalue:255
  */
-@property (strong) NSNumber<SDLInt> *dtcMask;
+@property (nullable, strong, nonatomic) NSNumber<SDLInt> *dtcMask;
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLGetDTCs.m b/SmartDeviceLink/SDLGetDTCs.m
index 99e903a95..3bbd551ff 100644
--- a/SmartDeviceLink/SDLGetDTCs.m
+++ b/SmartDeviceLink/SDLGetDTCs.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLGetDTCs
 
 - (instancetype)init {
@@ -45,12 +47,14 @@
     return [parameters sdl_objectForName:SDLNameECUName];
 }
 
-- (void)setDtcMask:(NSNumber<SDLInt> *)dtcMask {
+- (void)setDtcMask:(nullable NSNumber<SDLInt> *)dtcMask {
     [parameters sdl_setObject:dtcMask forName:SDLNameDTCMask];
 }
 
-- (NSNumber<SDLInt> *)dtcMask {
+- (nullable NSNumber<SDLInt> *)dtcMask {
     return [parameters sdl_objectForName:SDLNameDTCMask];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLGetDTCsResponse.h b/SmartDeviceLink/SDLGetDTCsResponse.h
index a07d9ced6..7368b42f2 100644
--- a/SmartDeviceLink/SDLGetDTCsResponse.h
+++ b/SmartDeviceLink/SDLGetDTCsResponse.h
@@ -9,9 +9,14 @@
  *
  * Since <b>SmartDeviceLink 2.0</b>
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLGetDTCsResponse : SDLRPCResponse
 
-@property (strong) NSNumber<SDLInt> *ecuHeader;
-@property (strong) NSMutableArray<NSString *> *dtc;
+@property (strong, nonatomic) NSNumber<SDLInt> *ecuHeader;
+@property (strong, nonatomic) NSMutableArray<NSString *> *dtc;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLGetDTCsResponse.m b/SmartDeviceLink/SDLGetDTCsResponse.m
index 05875bfaa..f1ead9716 100644
--- a/SmartDeviceLink/SDLGetDTCsResponse.m
+++ b/SmartDeviceLink/SDLGetDTCsResponse.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLGetDTCsResponse
 
 - (instancetype)init {
@@ -32,3 +34,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLGetVehicleData.h b/SmartDeviceLink/SDLGetVehicleData.h
index 65308786d..cee465c23 100644
--- a/SmartDeviceLink/SDLGetVehicleData.h
+++ b/SmartDeviceLink/SDLGetVehicleData.h
@@ -15,114 +15,119 @@
  * Since SmartDeviceLink 2.0<br/>
  * See SDLSubscribeVehicleData SDLUnsubscribeVehicleData
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLGetVehicleData : SDLRPCRequest
 
 - (instancetype)initWithAccelerationPedalPosition:(BOOL)accelerationPedalPosition airbagStatus:(BOOL)airbagStatus beltStatus:(BOOL)beltStatus bodyInformation:(BOOL)bodyInformation clusterModeStatus:(BOOL)clusterModeStatus deviceStatus:(BOOL)deviceStatus driverBraking:(BOOL)driverBraking eCallInfo:(BOOL)eCallInfo emergencyEvent:(BOOL)emergencyEvent engineTorque:(BOOL)engineTorque externalTemperature:(BOOL)externalTemperature fuelLevel:(BOOL)fuelLevel fuelLevelState:(BOOL)fuelLevelState gps:(BOOL)gps headLampStatus:(BOOL)headLampStatus instantFuelConsumption:(BOOL)instantFuelConsumption myKey:(BOOL)myKey odometer:(BOOL)odometer prndl:(BOOL)prndl rpm:(BOOL)rpm speed:(BOOL)speed steeringWheelAngle:(BOOL)steeringWheelAngle tirePressure:(BOOL)tirePressure vin:(BOOL)vin wiperStatus:(BOOL)wiperStatus;
 /**
  * @abstract A boolean value. If true, requests Gps data
  */
-@property (strong) NSNumber<SDLBool> *gps;
+@property (nullable, strong, nonatomic) NSNumber<SDLBool> *gps;
 
 /**
  * @abstract A boolean value. If true, requests speed data
  */
-@property (strong) NSNumber<SDLBool> *speed;
+@property (nullable, strong, nonatomic) NSNumber<SDLBool> *speed;
 
 /**
  * @abstract A boolean value. If true, requests rpm data
  */
-@property (strong) NSNumber<SDLBool> *rpm;
+@property (nullable, strong, nonatomic) NSNumber<SDLBool> *rpm;
 
 /**
  * @abstract A boolean value. If true, requests FuelLevel data
  */
-@property (strong) NSNumber<SDLBool> *fuelLevel;
+@property (nullable, strong, nonatomic) NSNumber<SDLBool> *fuelLevel;
 
 /**
  * @abstract A boolean value. If true, requests fuelLevel_State data
  */
-@property (strong) NSNumber<SDLBool> *fuelLevel_State;
+@property (nullable, strong, nonatomic) NSNumber<SDLBool> *fuelLevel_State;
 
 /**
  * @abstract A boolean value. If true, requests instantFuelConsumption data
  */
-@property (strong) NSNumber<SDLBool> *instantFuelConsumption;
+@property (nullable, strong, nonatomic) NSNumber<SDLBool> *instantFuelConsumption;
 
 /**
  * @abstract A boolean value. If true, requests externalTemperature data
  */
-@property (strong) NSNumber<SDLBool> *externalTemperature;
+@property (nullable, strong, nonatomic) NSNumber<SDLBool> *externalTemperature;
 
 /**
  * @abstract A boolean value. If true, requests Vehicle Identification Number
  */
-@property (strong) NSNumber<SDLBool> *vin;
+@property (nullable, strong, nonatomic) NSNumber<SDLBool> *vin;
 
 /**
  * @abstract A boolean value. If true, requests Currently selected gear data
  */
-@property (strong) NSNumber<SDLBool> *prndl;
+@property (nullable, strong, nonatomic) NSNumber<SDLBool> *prndl;
 
 /**
  * @abstract A boolean value. If true, requests tire pressure status data
  */
-@property (strong) NSNumber<SDLBool> *tirePressure;
+@property (nullable, strong, nonatomic) NSNumber<SDLBool> *tirePressure;
 
 /**
  * @abstract A boolean value. If true, requests odometer data
  */
-@property (strong) NSNumber<SDLBool> *odometer;
+@property (nullable, strong, nonatomic) NSNumber<SDLBool> *odometer;
 
 /**
  * @abstract A boolean value. If true, requests belt Status data
  */
-@property (strong) NSNumber<SDLBool> *beltStatus;
+@property (nullable, strong, nonatomic) NSNumber<SDLBool> *beltStatus;
 
 /**
  * @abstract A boolean value. If true, requests body Information data
  */
-@property (strong) NSNumber<SDLBool> *bodyInformation;
+@property (nullable, strong, nonatomic) NSNumber<SDLBool> *bodyInformation;
 
 /**
  * @abstract A boolean value. If true, requests device Status data
  */
-@property (strong) NSNumber<SDLBool> *deviceStatus;
+@property (nullable, strong, nonatomic) NSNumber<SDLBool> *deviceStatus;
 
 /**
  * @abstract A boolean value. If true, requests driver Braking data
  */
-@property (strong) NSNumber<SDLBool> *driverBraking;
+@property (nullable, strong, nonatomic) NSNumber<SDLBool> *driverBraking;
 
 /**
  * @abstract A boolean value. If true, requests wiper Status data
  */
-@property (strong) NSNumber<SDLBool> *wiperStatus;
+@property (nullable, strong, nonatomic) NSNumber<SDLBool> *wiperStatus;
 
 /**
  * @abstract A boolean value. If true, requests Head Lamp Status data
  */
-@property (strong) NSNumber<SDLBool> *headLampStatus;
+@property (nullable, strong, nonatomic) NSNumber<SDLBool> *headLampStatus;
 
 /**
  * @abstract A boolean value. If true, requests Engine Torque data
  */
-@property (strong) NSNumber<SDLBool> *engineTorque;
+@property (nullable, strong, nonatomic) NSNumber<SDLBool> *engineTorque;
 
 /**
  * @abstract A boolean value. If true, means the accPedalPosition data has been
  * subscribed.
  */
-@property (strong) NSNumber<SDLBool> *accPedalPosition;
+@property (nullable, strong, nonatomic) NSNumber<SDLBool> *accPedalPosition;
 
 /**
  * @abstract A boolean value. If true, means the steeringWheelAngle data has been
  * subscribed.
  */
-@property (strong) NSNumber<SDLBool> *steeringWheelAngle;
-@property (strong) NSNumber<SDLBool> *eCallInfo;
-@property (strong) NSNumber<SDLBool> *airbagStatus;
-@property (strong) NSNumber<SDLBool> *emergencyEvent;
-@property (strong) NSNumber<SDLBool> *clusterModeStatus;
-@property (strong) NSNumber<SDLBool> *myKey;
+@property (nullable, strong, nonatomic) NSNumber<SDLBool> *steeringWheelAngle;
+@property (nullable, strong, nonatomic) NSNumber<SDLBool> *eCallInfo;
+@property (nullable, strong, nonatomic) NSNumber<SDLBool> *airbagStatus;
+@property (nullable, strong, nonatomic) NSNumber<SDLBool> *emergencyEvent;
+@property (nullable, strong, nonatomic) NSNumber<SDLBool> *clusterModeStatus;
+@property (nullable, strong, nonatomic) NSNumber<SDLBool> *myKey;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLGetVehicleData.m b/SmartDeviceLink/SDLGetVehicleData.m
index 4b1d97cd8..53a897b7d 100644
--- a/SmartDeviceLink/SDLGetVehicleData.m
+++ b/SmartDeviceLink/SDLGetVehicleData.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLGetVehicleData
 
 - (instancetype)init {
@@ -50,204 +52,206 @@
     return self;
 }
 
-- (void)setGps:(NSNumber<SDLBool> *)gps {
+- (void)setGps:(nullable NSNumber<SDLBool> *)gps {
     [parameters sdl_setObject:gps forName:SDLNameGPS];
 }
 
-- (NSNumber<SDLBool> *)gps {
+- (nullable NSNumber<SDLBool> *)gps {
     return [parameters sdl_objectForName:SDLNameGPS];
 }
 
-- (void)setSpeed:(NSNumber<SDLBool> *)speed {
+- (void)setSpeed:(nullable NSNumber<SDLBool> *)speed {
     [parameters sdl_setObject:speed forName:SDLNameSpeed];
 }
 
-- (NSNumber<SDLBool> *)speed {
+- (nullable NSNumber<SDLBool> *)speed {
     return [parameters sdl_objectForName:SDLNameSpeed];
 }
 
-- (void)setRpm:(NSNumber<SDLBool> *)rpm {
+- (void)setRpm:(nullable NSNumber<SDLBool> *)rpm {
     [parameters sdl_setObject:rpm forName:SDLNameRPM];
 }
 
-- (NSNumber<SDLBool> *)rpm {
+- (nullable NSNumber<SDLBool> *)rpm {
     return [parameters sdl_objectForName:SDLNameRPM];
 }
 
-- (void)setFuelLevel:(NSNumber<SDLBool> *)fuelLevel {
+- (void)setFuelLevel:(nullable NSNumber<SDLBool> *)fuelLevel {
     [parameters sdl_setObject:fuelLevel forName:SDLNameFuelLevel];
 }
 
-- (NSNumber<SDLBool> *)fuelLevel {
+- (nullable NSNumber<SDLBool> *)fuelLevel {
     return [parameters sdl_objectForName:SDLNameFuelLevel];
 }
 
-- (void)setFuelLevel_State:(NSNumber<SDLBool> *)fuelLevel_State {
+- (void)setFuelLevel_State:(nullable NSNumber<SDLBool> *)fuelLevel_State {
     [parameters sdl_setObject:fuelLevel_State forName:SDLNameFuelLevelState];
 }
 
-- (NSNumber<SDLBool> *)fuelLevel_State {
+- (nullable NSNumber<SDLBool> *)fuelLevel_State {
     return [parameters sdl_objectForName:SDLNameFuelLevelState];
 }
 
-- (void)setInstantFuelConsumption:(NSNumber<SDLBool> *)instantFuelConsumption {
+- (void)setInstantFuelConsumption:(nullable NSNumber<SDLBool> *)instantFuelConsumption {
     [parameters sdl_setObject:instantFuelConsumption forName:SDLNameInstantFuelConsumption];
 }
 
-- (NSNumber<SDLBool> *)instantFuelConsumption {
+- (nullable NSNumber<SDLBool> *)instantFuelConsumption {
     return [parameters sdl_objectForName:SDLNameInstantFuelConsumption];
 }
 
-- (void)setExternalTemperature:(NSNumber<SDLBool> *)externalTemperature {
+- (void)setExternalTemperature:(nullable NSNumber<SDLBool> *)externalTemperature {
     [parameters sdl_setObject:externalTemperature forName:SDLNameExternalTemperature];
 }
 
-- (NSNumber<SDLBool> *)externalTemperature {
+- (nullable NSNumber<SDLBool> *)externalTemperature {
     return [parameters sdl_objectForName:SDLNameExternalTemperature];
 }
 
-- (void)setVin:(NSNumber<SDLBool> *)vin {
+- (void)setVin:(nullable NSNumber<SDLBool> *)vin {
     [parameters sdl_setObject:vin forName:SDLNameVIN];
 }
 
-- (NSNumber<SDLBool> *)vin {
+- (nullable NSNumber<SDLBool> *)vin {
     return [parameters sdl_objectForName:SDLNameVIN];
 }
 
-- (void)setPrndl:(NSNumber<SDLBool> *)prndl {
+- (void)setPrndl:(nullable NSNumber<SDLBool> *)prndl {
     [parameters sdl_setObject:prndl forName:SDLNamePRNDL];
 }
 
-- (NSNumber<SDLBool> *)prndl {
+- (nullable NSNumber<SDLBool> *)prndl {
     return [parameters sdl_objectForName:SDLNamePRNDL];
 }
 
-- (void)setTirePressure:(NSNumber<SDLBool> *)tirePressure {
+- (void)setTirePressure:(nullable NSNumber<SDLBool> *)tirePressure {
     [parameters sdl_setObject:tirePressure forName:SDLNameTirePressure];
 }
 
-- (NSNumber<SDLBool> *)tirePressure {
+- (nullable NSNumber<SDLBool> *)tirePressure {
     return [parameters sdl_objectForName:SDLNameTirePressure];
 }
 
-- (void)setOdometer:(NSNumber<SDLBool> *)odometer {
+- (void)setOdometer:(nullable NSNumber<SDLBool> *)odometer {
     [parameters sdl_setObject:odometer forName:SDLNameOdometer];
 }
 
-- (NSNumber<SDLBool> *)odometer {
+- (nullable NSNumber<SDLBool> *)odometer {
     return [parameters sdl_objectForName:SDLNameOdometer];
 }
 
-- (void)setBeltStatus:(NSNumber<SDLBool> *)beltStatus {
+- (void)setBeltStatus:(nullable NSNumber<SDLBool> *)beltStatus {
     [parameters sdl_setObject:beltStatus forName:SDLNameBeltStatus];
 }
 
-- (NSNumber<SDLBool> *)beltStatus {
+- (nullable NSNumber<SDLBool> *)beltStatus {
     return [parameters sdl_objectForName:SDLNameBeltStatus];
 }
 
-- (void)setBodyInformation:(NSNumber<SDLBool> *)bodyInformation {
+- (void)setBodyInformation:(nullable NSNumber<SDLBool> *)bodyInformation {
     [parameters sdl_setObject:bodyInformation forName:SDLNameBodyInformation];
 }
 
-- (NSNumber<SDLBool> *)bodyInformation {
+- (nullable NSNumber<SDLBool> *)bodyInformation {
     return [parameters sdl_objectForName:SDLNameBodyInformation];
 }
 
-- (void)setDeviceStatus:(NSNumber<SDLBool> *)deviceStatus {
+- (void)setDeviceStatus:(nullable NSNumber<SDLBool> *)deviceStatus {
     [parameters sdl_setObject:deviceStatus forName:SDLNameDeviceStatus];
 }
 
-- (NSNumber<SDLBool> *)deviceStatus {
+- (nullable NSNumber<SDLBool> *)deviceStatus {
     return [parameters sdl_objectForName:SDLNameDeviceStatus];
 }
 
-- (void)setDriverBraking:(NSNumber<SDLBool> *)driverBraking {
+- (void)setDriverBraking:(nullable NSNumber<SDLBool> *)driverBraking {
     [parameters sdl_setObject:driverBraking forName:SDLNameDriverBraking];
 }
 
-- (NSNumber<SDLBool> *)driverBraking {
+- (nullable NSNumber<SDLBool> *)driverBraking {
     return [parameters sdl_objectForName:SDLNameDriverBraking];
 }
 
-- (void)setWiperStatus:(NSNumber<SDLBool> *)wiperStatus {
+- (void)setWiperStatus:(nullable NSNumber<SDLBool> *)wiperStatus {
     [parameters sdl_setObject:wiperStatus forName:SDLNameWiperStatus];
 }
 
-- (NSNumber<SDLBool> *)wiperStatus {
+- (nullable NSNumber<SDLBool> *)wiperStatus {
     return [parameters sdl_objectForName:SDLNameWiperStatus];
 }
 
-- (void)setHeadLampStatus:(NSNumber<SDLBool> *)headLampStatus {
+- (void)setHeadLampStatus:(nullable NSNumber<SDLBool> *)headLampStatus {
     [parameters sdl_setObject:headLampStatus forName:SDLNameHeadLampStatus];
 }
 
-- (NSNumber<SDLBool> *)headLampStatus {
+- (nullable NSNumber<SDLBool> *)headLampStatus {
     return [parameters sdl_objectForName:SDLNameHeadLampStatus];
 }
 
-- (void)setEngineTorque:(NSNumber<SDLBool> *)engineTorque {
+- (void)setEngineTorque:(nullable NSNumber<SDLBool> *)engineTorque {
     [parameters sdl_setObject:engineTorque forName:SDLNameEngineTorque];
 }
 
-- (NSNumber<SDLBool> *)engineTorque {
+- (nullable NSNumber<SDLBool> *)engineTorque {
     return [parameters sdl_objectForName:SDLNameEngineTorque];
 }
 
-- (void)setAccPedalPosition:(NSNumber<SDLBool> *)accPedalPosition {
+- (void)setAccPedalPosition:(nullable NSNumber<SDLBool> *)accPedalPosition {
     [parameters sdl_setObject:accPedalPosition forName:SDLNameAccelerationPedalPosition];
 }
 
-- (NSNumber<SDLBool> *)accPedalPosition {
+- (nullable NSNumber<SDLBool> *)accPedalPosition {
     return [parameters sdl_objectForName:SDLNameAccelerationPedalPosition];
 }
 
-- (void)setSteeringWheelAngle:(NSNumber<SDLBool> *)steeringWheelAngle {
+- (void)setSteeringWheelAngle:(nullable NSNumber<SDLBool> *)steeringWheelAngle {
     [parameters sdl_setObject:steeringWheelAngle forName:SDLNameSteeringWheelAngle];
 }
 
-- (NSNumber<SDLBool> *)steeringWheelAngle {
+- (nullable NSNumber<SDLBool> *)steeringWheelAngle {
     return [parameters sdl_objectForName:SDLNameSteeringWheelAngle];
 }
 
-- (void)setECallInfo:(NSNumber<SDLBool> *)eCallInfo {
+- (void)setECallInfo:(nullable NSNumber<SDLBool> *)eCallInfo {
     [parameters sdl_setObject:eCallInfo forName:SDLNameECallInfo];
 }
 
-- (NSNumber<SDLBool> *)eCallInfo {
+- (nullable NSNumber<SDLBool> *)eCallInfo {
     return [parameters sdl_objectForName:SDLNameECallInfo];
 }
 
-- (void)setAirbagStatus:(NSNumber<SDLBool> *)airbagStatus {
+- (void)setAirbagStatus:(nullable NSNumber<SDLBool> *)airbagStatus {
     [parameters sdl_setObject:airbagStatus forName:SDLNameAirbagStatus];
 }
 
-- (NSNumber<SDLBool> *)airbagStatus {
+- (nullable NSNumber<SDLBool> *)airbagStatus {
     return [parameters sdl_objectForName:SDLNameAirbagStatus];
 }
 
-- (void)setEmergencyEvent:(NSNumber<SDLBool> *)emergencyEvent {
+- (void)setEmergencyEvent:(nullable NSNumber<SDLBool> *)emergencyEvent {
     [parameters sdl_setObject:emergencyEvent forName:SDLNameEmergencyEvent];
 }
 
-- (NSNumber<SDLBool> *)emergencyEvent {
+- (nullable NSNumber<SDLBool> *)emergencyEvent {
     return [parameters sdl_objectForName:SDLNameEmergencyEvent];
 }
 
-- (void)setClusterModeStatus:(NSNumber<SDLBool> *)clusterModeStatus {
+- (void)setClusterModeStatus:(nullable NSNumber<SDLBool> *)clusterModeStatus {
     [parameters sdl_setObject:clusterModeStatus forName:SDLNameClusterModeStatus];
 }
 
-- (NSNumber<SDLBool> *)clusterModeStatus {
+- (nullable NSNumber<SDLBool> *)clusterModeStatus {
     return [parameters sdl_objectForName:SDLNameClusterModeStatus];
 }
 
-- (void)setMyKey:(NSNumber<SDLBool> *)myKey {
+- (void)setMyKey:(nullable NSNumber<SDLBool> *)myKey {
     [parameters sdl_setObject:myKey forName:SDLNameMyKey];
 }
 
-- (NSNumber<SDLBool> *)myKey {
+- (nullable NSNumber<SDLBool> *)myKey {
     return [parameters sdl_objectForName:SDLNameMyKey];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLGetVehicleDataResponse.h b/SmartDeviceLink/SDLGetVehicleDataResponse.h
index d8a4c64ca..240f9907b 100644
--- a/SmartDeviceLink/SDLGetVehicleDataResponse.h
+++ b/SmartDeviceLink/SDLGetVehicleDataResponse.h
@@ -27,111 +27,116 @@
  *
  * Since SmartDeviceLink 2.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLGetVehicleDataResponse : SDLRPCResponse
 
 /**
  * @abstract A SDLGPSData* value. See GPSData.
  */
-@property (strong) SDLGPSData *gps;
+@property (nullable, strong, nonatomic) SDLGPSData *gps;
 
 /**
  * @abstract The vehicle speed in kilometers per hour.
  */
-@property (strong) NSNumber<SDLFloat> *speed;
+@property (nullable, strong, nonatomic) NSNumber<SDLFloat> *speed;
 
 /**
  * @abstract The number of revolutions per minute of the engine.
  */
-@property (strong) NSNumber<SDLInt> *rpm;
+@property (nullable, strong, nonatomic) NSNumber<SDLInt> *rpm;
 
 /**
  * @abstract The fuel level in the tank (percentage)
  */
-@property (strong) NSNumber<SDLFloat> *fuelLevel;
+@property (nullable, strong, nonatomic) NSNumber<SDLFloat> *fuelLevel;
 
 /**
  * @abstract A SDLComponentVolumeStatus* value. The fuel level state.
  */
-@property (strong) SDLComponentVolumeStatus fuelLevel_State;
+@property (nullable, strong, nonatomic) SDLComponentVolumeStatus fuelLevel_State;
 
 /**
  * @abstract The instantaneous fuel consumption in microlitres.
  */
-@property (strong) NSNumber<SDLFloat> *instantFuelConsumption;
+@property (nullable, strong, nonatomic) NSNumber<SDLFloat> *instantFuelConsumption;
 
 /**
  * @abstract The external temperature in degrees celsius.
  */
-@property (strong) NSNumber<SDLFloat> *externalTemperature;
+@property (nullable, strong, nonatomic) NSNumber<SDLFloat> *externalTemperature;
 
 /**
  * @abstract The Vehicle Identification Number
  */
-@property (strong) NSString *vin;
+@property (nullable, strong, nonatomic) NSString *vin;
 
 /**
  * @abstract See PRNDL.
  */
-@property (strong) SDLPRNDL prndl;
+@property (nullable, strong, nonatomic) SDLPRNDL prndl;
 
 /**
  * @abstract A SDLTireStatus* value. See TireStatus.
  */
-@property (strong) SDLTireStatus *tirePressure;
+@property (nullable, strong, nonatomic) SDLTireStatus *tirePressure;
 
 /**
  * @abstract Odometer reading in km.
  */
-@property (strong) NSNumber<SDLInt> *odometer;
+@property (nullable, strong, nonatomic) NSNumber<SDLInt> *odometer;
 
 /**
  * @abstract A SDLBeltStatus* value. The status of the seat belts.
  */
-@property (strong) SDLBeltStatus *beltStatus;
+@property (nullable, strong, nonatomic) SDLBeltStatus *beltStatus;
 
 /**
  * @abstract A SDLBodyInformation* value. The body information including power modes.
  */
-@property (strong) SDLBodyInformation *bodyInformation;
+@property (nullable, strong, nonatomic) SDLBodyInformation *bodyInformation;
 
 /**
  * @abstract A SDLDeviceStatus* value. The device status including signal and battery strength.
  */
-@property (strong) SDLDeviceStatus *deviceStatus;
+@property (nullable, strong, nonatomic) SDLDeviceStatus *deviceStatus;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The status of the brake pedal.
  */
-@property (strong) SDLVehicleDataEventStatus driverBraking;
+@property (nullable, strong, nonatomic) SDLVehicleDataEventStatus driverBraking;
 
 /**
  * @abstract A SDLWiperStatus* value. The status of the wipers.
  */
-@property (strong) SDLWiperStatus wiperStatus;
+@property (nullable, strong, nonatomic) SDLWiperStatus wiperStatus;
 
 /**
  * @abstract A SDLHeadLampStatus* value. Status of the head lamps.
  */
-@property (strong) SDLHeadLampStatus *headLampStatus;
+@property (nullable, strong, nonatomic) SDLHeadLampStatus *headLampStatus;
 
 /**
  * @abstract Torque value for engine (in Nm) on non-diesel variants.
  */
-@property (strong) NSNumber<SDLFloat> *engineTorque;
+@property (nullable, strong, nonatomic) NSNumber<SDLFloat> *engineTorque;
 
 /**
  * @abstract Accelerator pedal position (percentage depressed)
  */
-@property (strong) NSNumber<SDLFloat> *accPedalPosition;
+@property (nullable, strong, nonatomic) NSNumber<SDLFloat> *accPedalPosition;
 
 /**
  * @abstract Current angle of the steering wheel (in deg)
  */
-@property (strong) NSNumber<SDLFloat> *steeringWheelAngle;
-@property (strong) SDLECallInfo *eCallInfo;
-@property (strong) SDLAirbagStatus *airbagStatus;
-@property (strong) SDLEmergencyEvent *emergencyEvent;
-@property (strong) SDLClusterModeStatus *clusterModeStatus;
-@property (strong) SDLMyKey *myKey;
+@property (nullable, strong, nonatomic) NSNumber<SDLFloat> *steeringWheelAngle;
+@property (nullable, strong, nonatomic) SDLECallInfo *eCallInfo;
+@property (nullable, strong, nonatomic) SDLAirbagStatus *airbagStatus;
+@property (nullable, strong, nonatomic) SDLEmergencyEvent *emergencyEvent;
+@property (nullable, strong, nonatomic) SDLClusterModeStatus *clusterModeStatus;
+@property (nullable, strong, nonatomic) SDLMyKey *myKey;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLGetVehicleDataResponse.m b/SmartDeviceLink/SDLGetVehicleDataResponse.m
index 2a6717cdb..81b379b49 100644
--- a/SmartDeviceLink/SDLGetVehicleDataResponse.m
+++ b/SmartDeviceLink/SDLGetVehicleDataResponse.m
@@ -18,6 +18,7 @@
 #import "SDLNames.h"
 #import "SDLTireStatus.h"
 
+NS_ASSUME_NONNULL_BEGIN
 
 @implementation SDLGetVehicleDataResponse
 
@@ -27,204 +28,206 @@
     return self;
 }
 
-- (void)setGps:(SDLGPSData *)gps {
+- (void)setGps:(nullable SDLGPSData *)gps {
     [parameters sdl_setObject:gps forName:SDLNameGPS];
 }
 
-- (SDLGPSData *)gps {
+- (nullable SDLGPSData *)gps {
     return [parameters sdl_objectForName:SDLNameGPS ofClass:SDLGPSData.class];
 }
 
-- (void)setSpeed:(NSNumber<SDLFloat> *)speed {
+- (void)setSpeed:(nullable NSNumber<SDLFloat> *)speed {
     [parameters sdl_setObject:speed forName:SDLNameSpeed];
 }
 
-- (NSNumber<SDLFloat> *)speed {
+- (nullable NSNumber<SDLFloat> *)speed {
     return [parameters sdl_objectForName:SDLNameSpeed];
 }
 
-- (void)setRpm:(NSNumber<SDLInt> *)rpm {
+- (void)setRpm:(nullable NSNumber<SDLInt> *)rpm {
     [parameters sdl_setObject:rpm forName:SDLNameRPM];
 }
 
-- (NSNumber<SDLInt> *)rpm {
+- (nullable NSNumber<SDLInt> *)rpm {
     return [parameters sdl_objectForName:SDLNameRPM];
 }
 
-- (void)setFuelLevel:(NSNumber<SDLFloat> *)fuelLevel {
+- (void)setFuelLevel:(nullable NSNumber<SDLFloat> *)fuelLevel {
     [parameters sdl_setObject:fuelLevel forName:SDLNameFuelLevel];
 }
 
-- (NSNumber<SDLFloat> *)fuelLevel {
+- (nullable NSNumber<SDLFloat> *)fuelLevel {
     return [parameters sdl_objectForName:SDLNameFuelLevel];
 }
 
-- (void)setFuelLevel_State:(SDLComponentVolumeStatus)fuelLevel_State {
+- (void)setFuelLevel_State:(nullable SDLComponentVolumeStatus)fuelLevel_State {
     [parameters sdl_setObject:fuelLevel_State forName:SDLNameFuelLevelState];
 }
 
-- (SDLComponentVolumeStatus)fuelLevel_State {
+- (nullable SDLComponentVolumeStatus)fuelLevel_State {
     return [parameters sdl_objectForName:SDLNameFuelLevelState];
 }
 
-- (void)setInstantFuelConsumption:(NSNumber<SDLFloat> *)instantFuelConsumption {
+- (void)setInstantFuelConsumption:(nullable NSNumber<SDLFloat> *)instantFuelConsumption {
     [parameters sdl_setObject:instantFuelConsumption forName:SDLNameInstantFuelConsumption];
 }
 
-- (NSNumber<SDLFloat> *)instantFuelConsumption {
+- (nullable NSNumber<SDLFloat> *)instantFuelConsumption {
     return [parameters sdl_objectForName:SDLNameInstantFuelConsumption];
 }
 
-- (void)setExternalTemperature:(NSNumber<SDLFloat> *)externalTemperature {
+- (void)setExternalTemperature:(nullable NSNumber<SDLFloat> *)externalTemperature {
     [parameters sdl_setObject:externalTemperature forName:SDLNameExternalTemperature];
 }
 
-- (NSNumber<SDLFloat> *)externalTemperature {
+- (nullable NSNumber<SDLFloat> *)externalTemperature {
     return [parameters sdl_objectForName:SDLNameExternalTemperature];
 }
 
-- (void)setVin:(NSString *)vin {
+- (void)setVin:(nullable NSString *)vin {
     [parameters sdl_setObject:vin forName:SDLNameVIN];
 }
 
-- (NSString *)vin {
+- (nullable NSString *)vin {
     return [parameters sdl_objectForName:SDLNameVIN];
 }
 
-- (void)setPrndl:(SDLPRNDL)prndl {
+- (void)setPrndl:(nullable SDLPRNDL)prndl {
     [parameters sdl_setObject:prndl forName:SDLNamePRNDL];
 }
 
-- (SDLPRNDL)prndl {
+- (nullable SDLPRNDL)prndl {
     return [parameters sdl_objectForName:SDLNamePRNDL];
 }
 
-- (void)setTirePressure:(SDLTireStatus *)tirePressure {
+- (void)setTirePressure:(nullable SDLTireStatus *)tirePressure {
     [parameters sdl_setObject:tirePressure forName:SDLNameTirePressure];
 }
 
-- (SDLTireStatus *)tirePressure {
+- (nullable SDLTireStatus *)tirePressure {
     return [parameters sdl_objectForName:SDLNameTirePressure ofClass:SDLTireStatus.class];
 }
 
-- (void)setOdometer:(NSNumber<SDLInt> *)odometer {
+- (void)setOdometer:(nullable NSNumber<SDLInt> *)odometer {
     [parameters sdl_setObject:odometer forName:SDLNameOdometer];
 }
 
-- (NSNumber<SDLInt> *)odometer {
+- (nullable NSNumber<SDLInt> *)odometer {
     return [parameters sdl_objectForName:SDLNameOdometer];
 }
 
-- (void)setBeltStatus:(SDLBeltStatus *)beltStatus {
+- (void)setBeltStatus:(nullable SDLBeltStatus *)beltStatus {
     [parameters sdl_setObject:beltStatus forName:SDLNameBeltStatus];
 }
 
-- (SDLBeltStatus *)beltStatus {
+- (nullable SDLBeltStatus *)beltStatus {
     return [parameters sdl_objectForName:SDLNameBeltStatus ofClass:SDLBeltStatus.class];
 }
 
-- (void)setBodyInformation:(SDLBodyInformation *)bodyInformation {
+- (void)setBodyInformation:(nullable SDLBodyInformation *)bodyInformation {
     [parameters sdl_setObject:bodyInformation forName:SDLNameBodyInformation];
 }
 
-- (SDLBodyInformation *)bodyInformation {
+- (nullable SDLBodyInformation *)bodyInformation {
     return [parameters sdl_objectForName:SDLNameBodyInformation ofClass:SDLBodyInformation.class];
 }
 
-- (void)setDeviceStatus:(SDLDeviceStatus *)deviceStatus {
+- (void)setDeviceStatus:(nullable SDLDeviceStatus *)deviceStatus {
     [parameters sdl_setObject:deviceStatus forName:SDLNameDeviceStatus];
 }
 
-- (SDLDeviceStatus *)deviceStatus {
+- (nullable SDLDeviceStatus *)deviceStatus {
     return [parameters sdl_objectForName:SDLNameDeviceStatus ofClass:SDLDeviceStatus.class];
 }
 
-- (void)setDriverBraking:(SDLVehicleDataEventStatus)driverBraking {
+- (void)setDriverBraking:(nullable SDLVehicleDataEventStatus)driverBraking {
     [parameters sdl_setObject:driverBraking forName:SDLNameDriverBraking];
 }
 
-- (SDLVehicleDataEventStatus)driverBraking {
+- (nullable SDLVehicleDataEventStatus)driverBraking {
     return [parameters sdl_objectForName:SDLNameDriverBraking];
 }
 
-- (void)setWiperStatus:(SDLWiperStatus)wiperStatus {
+- (void)setWiperStatus:(nullable SDLWiperStatus)wiperStatus {
     [parameters sdl_setObject:wiperStatus forName:SDLNameWiperStatus];
 }
 
-- (SDLWiperStatus)wiperStatus {
+- (nullable SDLWiperStatus)wiperStatus {
     return [parameters sdl_objectForName:SDLNameWiperStatus];
 }
 
-- (void)setHeadLampStatus:(SDLHeadLampStatus *)headLampStatus {
+- (void)setHeadLampStatus:(nullable SDLHeadLampStatus *)headLampStatus {
     [parameters sdl_setObject:headLampStatus forName:SDLNameHeadLampStatus];
 }
 
-- (SDLHeadLampStatus *)headLampStatus {
+- (nullable SDLHeadLampStatus *)headLampStatus {
     return [parameters sdl_objectForName:SDLNameHeadLampStatus ofClass:SDLHeadLampStatus.class];
 }
 
-- (void)setEngineTorque:(NSNumber<SDLFloat> *)engineTorque {
+- (void)setEngineTorque:(nullable NSNumber<SDLFloat> *)engineTorque {
     [parameters sdl_setObject:engineTorque forName:SDLNameEngineTorque];
 }
 
-- (NSNumber<SDLFloat> *)engineTorque {
+- (nullable NSNumber<SDLFloat> *)engineTorque {
     return [parameters sdl_objectForName:SDLNameEngineTorque];
 }
 
-- (void)setAccPedalPosition:(NSNumber<SDLFloat> *)accPedalPosition {
+- (void)setAccPedalPosition:(nullable NSNumber<SDLFloat> *)accPedalPosition {
     [parameters sdl_setObject:accPedalPosition forName:SDLNameAccelerationPedalPosition];
 }
 
-- (NSNumber<SDLFloat> *)accPedalPosition {
+- (nullable NSNumber<SDLFloat> *)accPedalPosition {
     return [parameters sdl_objectForName:SDLNameAccelerationPedalPosition];
 }
 
-- (void)setSteeringWheelAngle:(NSNumber<SDLFloat> *)steeringWheelAngle {
+- (void)setSteeringWheelAngle:(nullable NSNumber<SDLFloat> *)steeringWheelAngle {
     [parameters sdl_setObject:steeringWheelAngle forName:SDLNameSteeringWheelAngle];
 }
 
-- (NSNumber<SDLFloat> *)steeringWheelAngle {
+- (nullable NSNumber<SDLFloat> *)steeringWheelAngle {
     return [parameters sdl_objectForName:SDLNameSteeringWheelAngle];
 }
 
-- (void)setECallInfo:(SDLECallInfo *)eCallInfo {
+- (void)setECallInfo:(nullable SDLECallInfo *)eCallInfo {
     [parameters sdl_setObject:eCallInfo forName:SDLNameECallInfo];
 }
 
-- (SDLECallInfo *)eCallInfo {
+- (nullable SDLECallInfo *)eCallInfo {
     return [parameters sdl_objectForName:SDLNameECallInfo ofClass:SDLECallInfo.class];
 }
 
-- (void)setAirbagStatus:(SDLAirbagStatus *)airbagStatus {
+- (void)setAirbagStatus:(nullable SDLAirbagStatus *)airbagStatus {
     [parameters sdl_setObject:airbagStatus forName:SDLNameAirbagStatus];
 }
 
-- (SDLAirbagStatus *)airbagStatus {
+- (nullable SDLAirbagStatus *)airbagStatus {
     return [parameters sdl_objectForName:SDLNameAirbagStatus ofClass:SDLAirbagStatus.class];
 }
 
-- (void)setEmergencyEvent:(SDLEmergencyEvent *)emergencyEvent {
+- (void)setEmergencyEvent:(nullable SDLEmergencyEvent *)emergencyEvent {
     [parameters sdl_setObject:emergencyEvent forName:SDLNameEmergencyEvent];
 }
 
-- (SDLEmergencyEvent *)emergencyEvent {
+- (nullable SDLEmergencyEvent *)emergencyEvent {
     return [parameters sdl_objectForName:SDLNameEmergencyEvent ofClass:SDLEmergencyEvent.class];
 }
 
-- (void)setClusterModeStatus:(SDLClusterModeStatus *)clusterModeStatus {
+- (void)setClusterModeStatus:(nullable SDLClusterModeStatus *)clusterModeStatus {
     [parameters sdl_setObject:clusterModeStatus forName:SDLNameClusterModeStatus];
 }
 
-- (SDLClusterModeStatus *)clusterModeStatus {
+- (nullable SDLClusterModeStatus *)clusterModeStatus {
     return [parameters sdl_objectForName:SDLNameClusterModeStatus ofClass:SDLClusterModeStatus.class];
 }
 
-- (void)setMyKey:(SDLMyKey *)myKey {
+- (void)setMyKey:(nullable SDLMyKey *)myKey {
     [parameters sdl_setObject:myKey forName:SDLNameMyKey];
 }
 
-- (SDLMyKey *)myKey {
+- (nullable SDLMyKey *)myKey {
     return [parameters sdl_objectForName:SDLNameMyKey ofClass:SDLMyKey.class];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLGetWaypoints.h b/SmartDeviceLink/SDLGetWaypoints.h
index 91f95ab9f..b0aaf96c5 100644
--- a/SmartDeviceLink/SDLGetWaypoints.h
+++ b/SmartDeviceLink/SDLGetWaypoints.h
@@ -5,6 +5,7 @@
 
 #import "SDLWaypointType.h"
 
+NS_ASSUME_NONNULL_BEGIN
 
 @interface SDLGetWayPoints : SDLRPCRequest
 
@@ -16,10 +17,16 @@
  *
  * Required
  */
-@property (strong, nonatomic) SDLWaypointType waypointType;
+@property (nullable, strong, nonatomic) SDLWaypointType waypointType;
 
 @end
 
+NS_ASSUME_NONNULL_END
+
+NS_ASSUME_NONNULL_BEGIN
+
 __deprecated_msg("Use SDLGetWayPoints instead")
     @interface SDLGetWaypoints : SDLGetWayPoints
-                                 @end
+@end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLGetWaypoints.m b/SmartDeviceLink/SDLGetWaypoints.m
index c02c8f069..5f974ff42 100644
--- a/SmartDeviceLink/SDLGetWaypoints.m
+++ b/SmartDeviceLink/SDLGetWaypoints.m
@@ -6,6 +6,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLGetWayPoints
 
 - (instancetype)init {
@@ -26,11 +28,11 @@
     return self;
 }
 
-- (void)setWaypointType:(SDLWaypointType)waypointType {
+- (void)setWaypointType:(nullable SDLWaypointType)waypointType {
     [parameters sdl_setObject:waypointType forName:SDLNameWaypointType];
 }
 
-- (SDLWaypointType)waypointType {
+- (nullable SDLWaypointType)waypointType {
     return [parameters sdl_objectForName:SDLNameWaypointType];
 }
 
@@ -39,3 +41,5 @@
 @implementation SDLGetWaypoints
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLGetWaypointsResponse.h b/SmartDeviceLink/SDLGetWaypointsResponse.h
index fe1489c7d..3da0b1a0d 100644
--- a/SmartDeviceLink/SDLGetWaypointsResponse.h
+++ b/SmartDeviceLink/SDLGetWaypointsResponse.h
@@ -5,6 +5,8 @@
 
 @class SDLLocationDetails;
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLGetWayPointsResponse : SDLRPCResponse
 
 /**
@@ -14,10 +16,12 @@
  *
  * Optional, Array size 1 - 10
  */
-@property (strong) NSArray<SDLLocationDetails *> *waypoints;
+@property (nullable, strong, nonatomic) NSArray<SDLLocationDetails *> *waypoints;
 
 @end
 
 __deprecated_msg("Use SDLGetWayPointsResponse instead")
     @interface SDLGetWaypointsResponse : SDLGetWayPointsResponse
-                                         @end
+@end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLGetWaypointsResponse.m b/SmartDeviceLink/SDLGetWaypointsResponse.m
index 75551d347..c2269f2d9 100644
--- a/SmartDeviceLink/SDLGetWaypointsResponse.m
+++ b/SmartDeviceLink/SDLGetWaypointsResponse.m
@@ -7,6 +7,8 @@
 #import "SDLLocationDetails.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLGetWayPointsResponse
 
 - (instancetype)init {
@@ -15,11 +17,11 @@
     return self;
 }
 
-- (void)setWaypoints:(NSArray<SDLLocationDetails *> *)waypoints {
+- (void)setWaypoints:(nullable NSArray<SDLLocationDetails *> *)waypoints {
     [parameters sdl_setObject:waypoints forName:SDLNameWaypoints];
 }
 
-- (NSArray<SDLLocationDetails *> *)waypoints {
+- (nullable NSArray<SDLLocationDetails *> *)waypoints {
     return [parameters sdl_objectsForName:SDLNameWaypoints ofClass:SDLLocationDetails.class];
 }
 
@@ -28,3 +30,5 @@
 @implementation SDLGetWaypointsResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLGlobals.h b/SmartDeviceLink/SDLGlobals.h
index fced9d4e9..367915d0c 100644
--- a/SmartDeviceLink/SDLGlobals.h
+++ b/SmartDeviceLink/SDLGlobals.h
@@ -8,6 +8,8 @@
 
 #import <Foundation/Foundation.h>
 
+NS_ASSUME_NONNULL_BEGIN
+
 #define SDL_SYSTEM_VERSION_LESS_THAN(version) ([[[UIDevice currentDevice] systemVersion] compare:version options:NSNumericSearch] == NSOrderedAscending)
 #define BLOCK_RETURN return
 
@@ -17,6 +19,8 @@
 @property (assign, nonatomic, readonly) NSUInteger maxMTUSize;
 @property (assign, nonatomic) NSUInteger maxHeadUnitVersion;
 
-+ (instancetype)globals;
++ (instancetype)sharedGlobals;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLGlobals.m b/SmartDeviceLink/SDLGlobals.m
index 7f122c01e..46036d1d4 100644
--- a/SmartDeviceLink/SDLGlobals.m
+++ b/SmartDeviceLink/SDLGlobals.m
@@ -8,8 +8,9 @@
 
 #import "SDLGlobals.h"
 
-static const NSUInteger maxProxyVersion = 4;
+NS_ASSUME_NONNULL_BEGIN
 
+static const NSUInteger maxProxyVersion = 4;
 
 @interface SDLGlobals ()
 
@@ -20,7 +21,7 @@ static const NSUInteger maxProxyVersion = 4;
 
 @implementation SDLGlobals
 
-+ (instancetype)globals {
++ (instancetype)sharedGlobals {
     static SDLGlobals *sharedGlobals = nil;
     static dispatch_once_t onceToken;
     dispatch_once(&onceToken, ^{
@@ -75,3 +76,5 @@ static const NSUInteger maxProxyVersion = 4;
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLHMICapabilities.h b/SmartDeviceLink/SDLHMICapabilities.h
index b20e5b27d..6c7fe43d5 100644
--- a/SmartDeviceLink/SDLHMICapabilities.h
+++ b/SmartDeviceLink/SDLHMICapabilities.h
@@ -4,6 +4,8 @@
 
 #import "SDLRPCStruct.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLHMICapabilities : SDLRPCStruct
 
 /**
@@ -11,13 +13,15 @@
  
  Boolean value. Optional.
  */
-@property (copy, nonatomic) NSNumber<SDLBool> *navigation;
+@property (nullable, copy, nonatomic) NSNumber<SDLBool> *navigation;
 
 /**
  Availability of build in phone. True: Available, False: Not Available
  
  Boolean value. Optional.
  */
-@property (copy, nonatomic) NSNumber<SDLBool> *phoneCall;
+@property (nullable, copy, nonatomic) NSNumber<SDLBool> *phoneCall;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLHMICapabilities.m b/SmartDeviceLink/SDLHMICapabilities.m
index df285685c..0d2b39dfa 100644
--- a/SmartDeviceLink/SDLHMICapabilities.m
+++ b/SmartDeviceLink/SDLHMICapabilities.m
@@ -7,22 +7,26 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLHMICapabilities
 
-- (void)setNavigation:(NSNumber<SDLBool> *)navigation {
+- (void)setNavigation:(nullable NSNumber<SDLBool> *)navigation {
     [store sdl_setObject:navigation forName:SDLNameNavigation];
 }
 
-- (NSNumber<SDLBool> *)navigation {
+- (nullable NSNumber<SDLBool> *)navigation {
     return [store sdl_objectForName:SDLNameNavigation];
 }
 
-- (void)setPhoneCall:(NSNumber<SDLBool> *)phoneCall {
+- (void)setPhoneCall:(nullable NSNumber<SDLBool> *)phoneCall {
     [store sdl_setObject:phoneCall forName:SDLNamePhoneCall];
 }
 
-- (NSNumber<SDLBool> *)phoneCall {
+- (nullable NSNumber<SDLBool> *)phoneCall {
     return [store sdl_objectForName:SDLNamePhoneCall];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLHMIPermissions.h b/SmartDeviceLink/SDLHMIPermissions.h
index bd5475751..a37f867e6 100644
--- a/SmartDeviceLink/SDLHMIPermissions.h
+++ b/SmartDeviceLink/SDLHMIPermissions.h
@@ -11,6 +11,9 @@
  * 
  * @since SDL 2.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLHMIPermissions : SDLRPCStruct
 
 /**
@@ -20,7 +23,7 @@
  *
  * Required, Array of SDLHMILevel, Array size 0 - 100
  */
-@property (strong) NSMutableArray<SDLHMILevel> *allowed;
+@property (strong, nonatomic) NSMutableArray<SDLHMILevel> *allowed;
 
 /**
  * @abstract a set of all HMI levels that are prohibited for this given RPC
@@ -29,6 +32,8 @@
  *
  * Required, Array of SDLHMILevel, Array size 0 - 100
  */
-@property (strong) NSMutableArray<SDLHMILevel> *userDisallowed;
+@property (strong, nonatomic) NSMutableArray<SDLHMILevel> *userDisallowed;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLHMIPermissions.m b/SmartDeviceLink/SDLHMIPermissions.m
index 3fedfd0f8..620c9ca6f 100644
--- a/SmartDeviceLink/SDLHMIPermissions.m
+++ b/SmartDeviceLink/SDLHMIPermissions.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLHMIPermissions
 
 - (void)setAllowed:(NSMutableArray<SDLHMILevel> *)allowed {
@@ -26,3 +28,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLHeadLampStatus.h b/SmartDeviceLink/SDLHeadLampStatus.h
index 7ec8c14e3..f695fdb2d 100644
--- a/SmartDeviceLink/SDLHeadLampStatus.h
+++ b/SmartDeviceLink/SDLHeadLampStatus.h
@@ -9,17 +9,22 @@
 /**
  * Status of the head lamps
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLHeadLampStatus : SDLRPCStruct
 
 /**
  * @abstract A boolean value. Status of the low beam lamps.
  */
-@property (strong) NSNumber<SDLBool> *lowBeamsOn;
+@property (strong, nonatomic) NSNumber<SDLBool> *lowBeamsOn;
 /**
  * @abstract A boolean value. Status of the high beam lamps.
  */
-@property (strong) NSNumber<SDLBool> *highBeamsOn;
+@property (strong, nonatomic) NSNumber<SDLBool> *highBeamsOn;
 
-@property (strong) SDLAmbientLightStatus ambientLightSensorStatus;
+@property (nullable, strong, nonatomic) SDLAmbientLightStatus ambientLightSensorStatus;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLHeadLampStatus.m b/SmartDeviceLink/SDLHeadLampStatus.m
index 4d3cb43b7..e26d3ab5d 100644
--- a/SmartDeviceLink/SDLHeadLampStatus.m
+++ b/SmartDeviceLink/SDLHeadLampStatus.m
@@ -7,6 +7,8 @@
 #import "SDLAmbientLightStatus.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLHeadLampStatus
 
 - (void)setLowBeamsOn:(NSNumber<SDLBool> *)lowBeamsOn {
@@ -25,12 +27,14 @@
     return [store sdl_objectForName:SDLNameHighBeamsOn];
 }
 
-- (void)setAmbientLightSensorStatus:(SDLAmbientLightStatus)ambientLightSensorStatus {
+- (void)setAmbientLightSensorStatus:(nullable SDLAmbientLightStatus)ambientLightSensorStatus {
     [store sdl_setObject:ambientLightSensorStatus forName:SDLNameAmbientLightSensorStatus];
 }
 
-- (SDLAmbientLightStatus)ambientLightSensorStatus {
+- (nullable SDLAmbientLightStatus)ambientLightSensorStatus {
     return [store sdl_objectForName:SDLNameAmbientLightSensorStatus];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLHexUtility.h b/SmartDeviceLink/SDLHexUtility.h
index 7b639a7af..95b564b57 100644
--- a/SmartDeviceLink/SDLHexUtility.h
+++ b/SmartDeviceLink/SDLHexUtility.h
@@ -5,9 +5,13 @@
 
 #import <Foundation/Foundation.h>
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLHexUtility : NSObject
 
 + (NSString *)getHexString:(UInt8 *)bytes length:(NSUInteger)length;
 + (NSString *)getHexString:(NSData *)data;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLHexUtility.m b/SmartDeviceLink/SDLHexUtility.m
index 0787d804a..b103322ed 100644
--- a/SmartDeviceLink/SDLHexUtility.m
+++ b/SmartDeviceLink/SDLHexUtility.m
@@ -7,6 +7,8 @@
 
 @implementation SDLHexUtility
 
+NS_ASSUME_NONNULL_BEGIN
+
 // Using this function as a fail-safe, because we know this is successful.
 + (NSString *)getHexString:(UInt8 *)bytes length:(NSUInteger)length {
     NSMutableString *ret = [NSMutableString stringWithCapacity:(length * 2)];
@@ -58,3 +60,5 @@ NSString *getHexString(NSData *data) {
 
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLIAPSession.h b/SmartDeviceLink/SDLIAPSession.h
index d21343894..6442540c4 100644
--- a/SmartDeviceLink/SDLIAPSession.h
+++ b/SmartDeviceLink/SDLIAPSession.h
@@ -8,15 +8,17 @@
 
 @class SDLStreamDelegate;
 
+NS_ASSUME_NONNULL_BEGIN
+
 typedef void (^SessionCompletionHandler)(BOOL success);
 
 @interface SDLIAPSession : NSObject
 
-@property (strong, atomic) EAAccessory *accessory;
-@property (strong, atomic) NSString *protocol;
-@property (strong, atomic) EASession *easession;
-@property (weak) id<SDLIAPSessionDelegate> delegate;
-@property (strong, atomic) SDLStreamDelegate *streamDelegate;
+@property (nullable, strong, nonatomic) EAAccessory *accessory;
+@property (nullable, strong, nonatomic) NSString *protocol;
+@property (nullable, strong, nonatomic) EASession *easession;
+@property (nullable, weak, nonatomic) id<SDLIAPSessionDelegate> delegate;
+@property (nullable, strong, nonatomic) SDLStreamDelegate *streamDelegate;
 
 - (instancetype)initWithAccessory:(EAAccessory *)accessory
                       forProtocol:(NSString *)protocol;
@@ -25,3 +27,5 @@ typedef void (^SessionCompletionHandler)(BOOL success);
 - (void)stop;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLIAPSession.m b/SmartDeviceLink/SDLIAPSession.m
index 5020b2081..7bbc96fa1 100644
--- a/SmartDeviceLink/SDLIAPSession.m
+++ b/SmartDeviceLink/SDLIAPSession.m
@@ -7,11 +7,12 @@
 #import "SDLStreamDelegate.h"
 #import "SDLTimer.h"
 
+NS_ASSUME_NONNULL_BEGIN
 
 @interface SDLIAPSession ()
 
-@property (assign) BOOL isInputStreamOpen;
-@property (assign) BOOL isOutputStreamOpen;
+@property (assign, nonatomic) BOOL isInputStreamOpen;
+@property (assign, nonatomic) BOOL isOutputStreamOpen;
 
 @end
 
@@ -26,11 +27,8 @@
 
     self = [super init];
     if (self) {
-        _delegate = nil;
         _accessory = accessory;
         _protocol = protocol;
-        _streamDelegate = nil;
-        _easession = nil;
         _isInputStreamOpen = NO;
         _isOutputStreamOpen = NO;
     }
@@ -141,16 +139,6 @@
     };
 }
 
-
-#pragma mark - Lifecycle Destruction
-
-- (void)dealloc {
-    self.delegate = nil;
-    self.accessory = nil;
-    self.protocol = nil;
-    self.streamDelegate = nil;
-    self.easession = nil;
-    [SDLDebugTool logInfo:@"SDLIAPSession Dealloc"];
-}
-
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLIAPSessionDelegate.h b/SmartDeviceLink/SDLIAPSessionDelegate.h
index 6ec7e189b..b391a38fc 100644
--- a/SmartDeviceLink/SDLIAPSessionDelegate.h
+++ b/SmartDeviceLink/SDLIAPSessionDelegate.h
@@ -5,9 +5,13 @@
 #import <Foundation/Foundation.h>
 @class SDLIAPSession;
 
+NS_ASSUME_NONNULL_BEGIN
+
 @protocol SDLIAPSessionDelegate
 
 - (void)onSessionInitializationCompleteForSession:(SDLIAPSession *)session;
 - (void)onSessionStreamsEnded:(SDLIAPSession *)session;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLIAPTransport.h b/SmartDeviceLink/SDLIAPTransport.h
index ff082b9b3..94fd01bda 100644
--- a/SmartDeviceLink/SDLIAPTransport.h
+++ b/SmartDeviceLink/SDLIAPTransport.h
@@ -6,10 +6,13 @@
 #import "SDLAbstractTransport.h"
 #import "SDLIAPSessionDelegate.h"
 
+NS_ASSUME_NONNULL_BEGIN
 
 @interface SDLIAPTransport : SDLAbstractTransport <SDLIAPSessionDelegate>
 
-@property (strong, atomic) SDLIAPSession *controlSession;
-@property (strong, atomic) SDLIAPSession *session;
+@property (nullable, strong, nonatomic) SDLIAPSession *controlSession;
+@property (nullable, strong, nonatomic) SDLIAPSession *session;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLIAPTransport.m b/SmartDeviceLink/SDLIAPTransport.m
index a55fccf0b..e2a85bc78 100644
--- a/SmartDeviceLink/SDLIAPTransport.m
+++ b/SmartDeviceLink/SDLIAPTransport.m
@@ -15,6 +15,7 @@
 #import "SDLTimer.h"
 #import <CommonCrypto/CommonDigest.h>
 
+NS_ASSUME_NONNULL_BEGIN
 
 NSString *const legacyProtocolString = @"com.ford.sync.prot0";
 NSString *const controlProtocolString = @"com.smartdevicelink.prot0";
@@ -27,12 +28,11 @@ int const streamOpenTimeoutSeconds = 2;
 
 @interface SDLIAPTransport () {
     dispatch_queue_t _transmit_queue;
-    BOOL _alreadyDestructed;
 }
 
-@property (assign) int retryCounter;
-@property (assign) BOOL sessionSetupInProgress;
-@property (strong) SDLTimer *protocolIndexTimer;
+@property (assign, nonatomic) int retryCounter;
+@property (assign, nonatomic) BOOL sessionSetupInProgress;
+@property (nullable, strong, nonatomic) SDLTimer *protocolIndexTimer;
 
 @end
 
@@ -41,12 +41,8 @@ int const streamOpenTimeoutSeconds = 2;
 
 - (instancetype)init {
     if (self = [super init]) {
-        _alreadyDestructed = NO;
-        _session = nil;
-        _controlSession = nil;
         _retryCounter = 0;
         _sessionSetupInProgress = NO;
-        _protocolIndexTimer = nil;
         _transmit_queue = dispatch_queue_create("com.sdl.transport.iap.transmit", DISPATCH_QUEUE_SERIAL);
 
         [self sdl_startEventListening];
@@ -58,6 +54,12 @@ int const streamOpenTimeoutSeconds = 2;
 }
 
 
+- (void)dealloc {
+    [self disconnect];
+    [self sdl_stopEventListening];
+    [SDLDebugTool logInfo:@"SDLIAPTransport Dealloc" withType:SDLDebugType_Transport_iAP toOutput:SDLDebugOutput_All toGroup:self.debugConsoleGroupName];
+}
+
 #pragma mark - Notification Subscriptions
 
 - (void)sdl_startEventListening {
@@ -380,9 +382,9 @@ int const streamOpenTimeoutSeconds = 2;
     return ^(NSInputStream *istream) {
         __strong typeof(weakSelf) strongSelf = weakSelf;
 
-        uint8_t buf[[SDLGlobals globals].maxMTUSize];
+        uint8_t buf[[SDLGlobals sharedGlobals].maxMTUSize];
         while ([istream hasBytesAvailable]) {
-            NSInteger bytesRead = [istream read:buf maxLength:[SDLGlobals globals].maxMTUSize];
+            NSInteger bytesRead = [istream read:buf maxLength:[SDLGlobals sharedGlobals].maxMTUSize];
             NSData *dataIn = [NSData dataWithBytes:buf length:bytesRead];
 
             if (bytesRead > 0) {
@@ -450,26 +452,6 @@ int const streamOpenTimeoutSeconds = 2;
     return delay;
 }
 
-
-#pragma mark - Lifecycle Destruction
-
-- (void)sdl_destructObjects {
-    if (!_alreadyDestructed) {
-        _alreadyDestructed = YES;
-        [self sdl_stopEventListening];
-        self.controlSession = nil;
-        self.session = nil;
-        self.delegate = nil;
-    }
-}
-
-- (void)dispose {
-    [self sdl_destructObjects];
-}
-
-- (void)dealloc {
-    [self sdl_destructObjects];
-    [SDLDebugTool logInfo:@"SDLIAPTransport Dealloc" withType:SDLDebugType_Transport_iAP toOutput:SDLDebugOutput_All toGroup:self.debugConsoleGroupName];
-}
-
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLImage.h b/SmartDeviceLink/SDLImage.h
index c29dd66ce..cb21b9545 100644
--- a/SmartDeviceLink/SDLImage.h
+++ b/SmartDeviceLink/SDLImage.h
@@ -10,6 +10,9 @@
  * 
  * @since SDL 2.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLImage : SDLRPCStruct
 
 - (instancetype)initWithName:(NSString *)name ofType:(SDLImageType)imageType;
@@ -19,13 +22,15 @@
  *
  * Required, max length = 65535
  */
-@property (strong) NSString *value;
+@property (strong, nonatomic) NSString *value;
 
 /**
  * @abstract Describes, whether it is a static or dynamic image
  *
  * Required
  */
-@property (strong) SDLImageType imageType;
+@property (strong, nonatomic) SDLImageType imageType;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLImage.m b/SmartDeviceLink/SDLImage.m
index 2c89b1047..ebd7e09d4 100644
--- a/SmartDeviceLink/SDLImage.m
+++ b/SmartDeviceLink/SDLImage.m
@@ -6,6 +6,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLImage
 
 - (instancetype)initWithName:(NSString *)name ofType:(SDLImageType)imageType {
@@ -37,3 +39,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLImageField.h b/SmartDeviceLink/SDLImageField.h
index 69932c5c4..429e77343 100644
--- a/SmartDeviceLink/SDLImageField.h
+++ b/SmartDeviceLink/SDLImageField.h
@@ -8,10 +8,14 @@
 
 @class SDLImageResolution;
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLImageField : SDLRPCStruct
 
-@property (strong) SDLImageFieldName name;
-@property (strong) NSMutableArray<SDLFileType> *imageTypeSupported;
-@property (strong) SDLImageResolution *imageResolution;
+@property (strong, nonatomic) SDLImageFieldName name;
+@property (strong, nonatomic) NSMutableArray<SDLFileType> *imageTypeSupported;
+@property (nullable, strong, nonatomic) SDLImageResolution *imageResolution;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLImageField.m b/SmartDeviceLink/SDLImageField.m
index b9cde2a21..dfa223b3c 100644
--- a/SmartDeviceLink/SDLImageField.m
+++ b/SmartDeviceLink/SDLImageField.m
@@ -8,6 +8,8 @@
 #import "SDLImageResolution.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLImageField
 
 - (void)setName:(SDLImageFieldName)name {
@@ -26,12 +28,14 @@
     return [store sdl_enumsForName:SDLNameImageTypeSupported];
 }
 
-- (void)setImageResolution:(SDLImageResolution *)imageResolution {
+- (void)setImageResolution:(nullable SDLImageResolution *)imageResolution {
     [store sdl_setObject:imageResolution forName:SDLNameImageResolution];
 }
 
-- (SDLImageResolution *)imageResolution {
+- (nullable SDLImageResolution *)imageResolution {
     return [store sdl_objectForName:SDLNameImageResolution ofClass:SDLImageResolution.class];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLImageResolution.h b/SmartDeviceLink/SDLImageResolution.h
index ca086ea61..d9b25eec7 100644
--- a/SmartDeviceLink/SDLImageResolution.h
+++ b/SmartDeviceLink/SDLImageResolution.h
@@ -4,9 +4,13 @@
 
 #import "SDLRPCMessage.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLImageResolution : SDLRPCStruct
 
-@property (strong) NSNumber<SDLInt> *resolutionWidth;
-@property (strong) NSNumber<SDLInt> *resolutionHeight;
+@property (strong, nonatomic) NSNumber<SDLInt> *resolutionWidth;
+@property (strong, nonatomic) NSNumber<SDLInt> *resolutionHeight;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLImageResolution.m b/SmartDeviceLink/SDLImageResolution.m
index 4375b1299..18b69fe6e 100644
--- a/SmartDeviceLink/SDLImageResolution.m
+++ b/SmartDeviceLink/SDLImageResolution.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLImageResolution
 
 - (void)setResolutionWidth:(NSNumber<SDLInt> *)resolutionWidth {
@@ -26,3 +28,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLKeyboardProperties.h b/SmartDeviceLink/SDLKeyboardProperties.h
index 8874436a3..576053bd9 100644
--- a/SmartDeviceLink/SDLKeyboardProperties.h
+++ b/SmartDeviceLink/SDLKeyboardProperties.h
@@ -7,14 +7,18 @@
 #import "SDLKeypressMode.h"
 #import "SDLLanguage.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLKeyboardProperties : SDLRPCStruct
 
-- (instancetype)initWithLanguage:(SDLLanguage)language layout:(SDLKeyboardLayout)layout keypressMode:(SDLKeypressMode)keypressMode limitedCharacterList:(NSArray<NSString *> *)limitedCharacterList autoCompleteText:(NSString *)autoCompleteText;
+- (instancetype)initWithLanguage:(nullable SDLLanguage)language layout:(nullable SDLKeyboardLayout)layout keypressMode:(nullable SDLKeypressMode)keypressMode limitedCharacterList:(nullable NSArray<NSString *> *)limitedCharacterList autoCompleteText:(nullable NSString *)autoCompleteText;
 
-@property (strong) SDLLanguage language;
-@property (strong) SDLKeyboardLayout keyboardLayout;
-@property (strong) SDLKeypressMode keypressMode;
-@property (strong) NSMutableArray<NSString *> *limitedCharacterList;
-@property (strong) NSString *autoCompleteText;
+@property (nullable, strong, nonatomic) SDLLanguage language;
+@property (nullable, strong, nonatomic) SDLKeyboardLayout keyboardLayout;
+@property (nullable, strong, nonatomic) SDLKeypressMode keypressMode;
+@property (nullable, strong, nonatomic) NSMutableArray<NSString *> *limitedCharacterList;
+@property (nullable, strong, nonatomic) NSString *autoCompleteText;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLKeyboardProperties.m b/SmartDeviceLink/SDLKeyboardProperties.m
index 45fbcfed5..90899cf17 100644
--- a/SmartDeviceLink/SDLKeyboardProperties.m
+++ b/SmartDeviceLink/SDLKeyboardProperties.m
@@ -6,9 +6,11 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLKeyboardProperties
 
-- (instancetype)initWithLanguage:(SDLLanguage)language layout:(SDLKeyboardLayout)layout keypressMode:(SDLKeypressMode)keypressMode limitedCharacterList:(NSArray<NSString *> *)limitedCharacterList autoCompleteText:(NSString *)autoCompleteText {
+- (instancetype)initWithLanguage:(nullable SDLLanguage)language layout:(nullable SDLKeyboardLayout)layout keypressMode:(nullable SDLKeypressMode)keypressMode limitedCharacterList:(nullable NSArray<NSString *> *)limitedCharacterList autoCompleteText:(nullable NSString *)autoCompleteText {
     self = [self init];
     if (!self) {
         return nil;
@@ -23,44 +25,46 @@
     return self;
 }
 
-- (void)setLanguage:(SDLLanguage)language {
+- (void)setLanguage:(nullable SDLLanguage)language {
     [store sdl_setObject:language forName:SDLNameLanguage];
 }
 
-- (SDLLanguage)language {
+- (nullable SDLLanguage)language {
     return [store sdl_objectForName:SDLNameLanguage];
 }
 
-- (void)setKeyboardLayout:(SDLKeyboardLayout)keyboardLayout {
+- (void)setKeyboardLayout:(nullable SDLKeyboardLayout)keyboardLayout {
     [store sdl_setObject:keyboardLayout forName:SDLNameKeyboardLayout];
 }
 
-- (SDLKeyboardLayout)keyboardLayout {
+- (nullable SDLKeyboardLayout)keyboardLayout {
     return [store sdl_objectForName:SDLNameKeyboardLayout];
 }
 
-- (void)setKeypressMode:(SDLKeypressMode)keypressMode {
+- (void)setKeypressMode:(nullable SDLKeypressMode)keypressMode {
     [store sdl_setObject:keypressMode forName:SDLNameKeypressMode];
 }
 
-- (SDLKeypressMode)keypressMode {
+- (nullable SDLKeypressMode)keypressMode {
     return [store sdl_objectForName:SDLNameKeypressMode];
 }
 
-- (void)setLimitedCharacterList:(NSMutableArray<NSString *> *)limitedCharacterList {
+- (void)setLimitedCharacterList:(nullable NSMutableArray<NSString *> *)limitedCharacterList {
     [store sdl_setObject:limitedCharacterList forName:SDLNameLimitedCharacterList];
 }
 
-- (NSMutableArray<NSString *> *)limitedCharacterList {
+- (nullable NSMutableArray<NSString *> *)limitedCharacterList {
     return [store sdl_objectForName:SDLNameLimitedCharacterList];
 }
 
-- (void)setAutoCompleteText:(NSString *)autoCompleteText {
+- (void)setAutoCompleteText:(nullable NSString *)autoCompleteText {
     [store sdl_setObject:autoCompleteText forName:SDLNameAutoCompleteText];
 }
 
-- (NSString *)autoCompleteText {
+- (nullable NSString *)autoCompleteText {
     return [store sdl_objectForName:SDLNameAutoCompleteText];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLLifecycleManager.m b/SmartDeviceLink/SDLLifecycleManager.m
index 0ddf64a03..ebd3b5e0b 100644
--- a/SmartDeviceLink/SDLLifecycleManager.m
+++ b/SmartDeviceLink/SDLLifecycleManager.m
@@ -175,7 +175,8 @@ SDLLifecycleState *const SDLLifecycleStateReady = @"Ready";
     self.lastCorrelationId = 0;
     self.hmiLevel = nil;
 
-    [self sdl_disposeProxy]; // call this method instead of stopProxy to avoid double-dispatching
+    [SDLDebugTool logInfo:@"Stopping Proxy"];
+    self.proxy = nil;
     [self.delegate managerDidDisconnect];
 
     [self startWithReadyHandler:self.readyHandler]; // Start up again to start watching for new connections
@@ -377,13 +378,6 @@ SDLLifecycleState *const SDLLifecycleStateReady = @"Ready";
 
 
 #pragma mark Helper Methods
-
-- (void)sdl_disposeProxy {
-    [SDLDebugTool logInfo:@"Stop Proxy"];
-    [self.proxy dispose];
-    self.proxy = nil;
-}
-
 - (NSNumber<SDLInt> *)sdl_getNextCorrelationId {
     if (self.lastCorrelationId == UINT16_MAX) {
         self.lastCorrelationId = 0;
diff --git a/SmartDeviceLink/SDLListFiles.h b/SmartDeviceLink/SDLListFiles.h
index 61ae4c03b..28bf706b8 100644
--- a/SmartDeviceLink/SDLListFiles.h
+++ b/SmartDeviceLink/SDLListFiles.h
@@ -11,6 +11,11 @@
  *
  * Since <b>SmartDeviceLink 2.0</b>
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLListFiles : SDLRPCRequest
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLListFiles.m b/SmartDeviceLink/SDLListFiles.m
index d27963de2..9efc8f6cb 100644
--- a/SmartDeviceLink/SDLListFiles.m
+++ b/SmartDeviceLink/SDLListFiles.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLListFiles
 
 - (instancetype)init {
@@ -16,3 +18,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLListFilesResponse.h b/SmartDeviceLink/SDLListFilesResponse.h
index 47e6b3176..c07d617fe 100644
--- a/SmartDeviceLink/SDLListFilesResponse.h
+++ b/SmartDeviceLink/SDLListFilesResponse.h
@@ -9,9 +9,14 @@
  *
  * Since <b>SmartDeviceLink 2.0</b>
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLListFilesResponse : SDLRPCResponse
 
-@property (strong) NSMutableArray<NSString *> *filenames;
-@property (strong) NSNumber<SDLInt> *spaceAvailable;
+@property (nullable, strong, nonatomic) NSMutableArray<NSString *> *filenames;
+@property (strong, nonatomic) NSNumber<SDLInt> *spaceAvailable;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLListFilesResponse.m b/SmartDeviceLink/SDLListFilesResponse.m
index 8ae451edd..e803a83b5 100644
--- a/SmartDeviceLink/SDLListFilesResponse.m
+++ b/SmartDeviceLink/SDLListFilesResponse.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLListFilesResponse
 
 - (instancetype)init {
@@ -15,11 +17,11 @@
     return self;
 }
 
-- (void)setFilenames:(NSMutableArray<NSString *> *)filenames {
+- (void)setFilenames:(nullable NSMutableArray<NSString *> *)filenames {
     [parameters sdl_setObject:filenames forName:SDLNameFilenames];
 }
 
-- (NSMutableArray<NSString *> *)filenames {
+- (nullable NSMutableArray<NSString *> *)filenames {
     return [parameters objectForKey:SDLNameFilenames];
 }
 
@@ -32,3 +34,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLLocationCoordinate.h b/SmartDeviceLink/SDLLocationCoordinate.h
index dd2850f97..0fef535c2 100644
--- a/SmartDeviceLink/SDLLocationCoordinate.h
+++ b/SmartDeviceLink/SDLLocationCoordinate.h
@@ -3,6 +3,8 @@
 
 #import "SDLRPCStruct.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLLocationCoordinate : SDLRPCStruct
 
 /**
@@ -20,3 +22,5 @@
 @property (copy, nonatomic) NSNumber<SDLFloat> *longitudeDegrees;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLLocationCoordinate.m b/SmartDeviceLink/SDLLocationCoordinate.m
index f02283a83..79b3d4d56 100644
--- a/SmartDeviceLink/SDLLocationCoordinate.m
+++ b/SmartDeviceLink/SDLLocationCoordinate.m
@@ -6,6 +6,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLLocationCoordinate
 
 - (void)setLongitudeDegrees:(NSNumber<SDLFloat> *)longitudeDegrees {
@@ -25,3 +27,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLLocationDetails.h b/SmartDeviceLink/SDLLocationDetails.h
index 349a58265..3bce4d58c 100644
--- a/SmartDeviceLink/SDLLocationDetails.h
+++ b/SmartDeviceLink/SDLLocationDetails.h
@@ -7,6 +7,8 @@
 @class SDLImage;
 @class SDLOasisAddress;
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLLocationDetails : SDLRPCStruct
 
 /**
@@ -16,35 +18,35 @@
  *
  * Optional
  */
-@property (strong, nonatomic) SDLLocationCoordinate *coordinate;
+@property (nullable, strong, nonatomic) SDLLocationCoordinate *coordinate;
 
 /**
  * @abstract Name of location.
  *
  * Optional, Max length 500 chars
  */
-@property (copy, nonatomic) NSString *locationName;
+@property (nullable, copy, nonatomic) NSString *locationName;
 
 /**
  * @abstract Location address for display purposes only.
  *
  * Optional, Array of Strings, Array length 0 - 4, Max String length 500
  */
-@property (copy, nonatomic) NSArray<NSString *> *addressLines;
+@property (nullable, copy, nonatomic) NSArray<NSString *> *addressLines;
 
 /**
  * @abstract Description intended location / establishment.
  *
  * Optional, Max length 500 chars
  */
-@property (copy, nonatomic) NSString *locationDescription;
+@property (nullable, copy, nonatomic) NSString *locationDescription;
 
 /**
  * @abstract Phone number of location / establishment.
  *
  * Optional, Max length 500 chars
  */
-@property (copy, nonatomic) NSString *phoneNumber;
+@property (nullable, copy, nonatomic) NSString *phoneNumber;
 
 /**
  * @abstract Image / icon of intended location.
@@ -53,7 +55,7 @@
  *
  * Optional
  */
-@property (strong, nonatomic) SDLImage *locationImage;
+@property (nullable, strong, nonatomic) SDLImage *locationImage;
 
 /**
  * @abstract Address to be used by navigation engines for search.
@@ -62,7 +64,9 @@
  *
  * Optional
  */
-@property (strong) SDLOasisAddress *searchAddress;
+@property (nullable, strong, nonatomic) SDLOasisAddress *searchAddress;
 
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLLocationDetails.m b/SmartDeviceLink/SDLLocationDetails.m
index d62b914ad..ccf73cda4 100644
--- a/SmartDeviceLink/SDLLocationDetails.m
+++ b/SmartDeviceLink/SDLLocationDetails.m
@@ -9,62 +9,66 @@
 #import "SDLNames.h"
 #import "SDLOasisAddress.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLLocationDetails
 
-- (void)setCoordinate:(SDLLocationCoordinate *)coordinate {
+- (void)setCoordinate:(nullable SDLLocationCoordinate *)coordinate {
     [store sdl_setObject:coordinate forName:SDLNameLocationCoordinate];
 }
 
-- (SDLLocationCoordinate *)coordinate {
+- (nullable SDLLocationCoordinate *)coordinate {
     return [store sdl_objectForName:SDLNameLocationCoordinate ofClass:SDLLocationCoordinate.class];
 }
 
-- (void)setLocationName:(NSString *)locationName {
+- (void)setLocationName:(nullable NSString *)locationName {
     [store sdl_setObject:locationName forName:SDLNameLocationName];
 }
 
-- (NSString *)locationName {
+- (nullable NSString *)locationName {
     return [store sdl_objectForName:SDLNameLocationName];
 }
 
-- (void)setAddressLines:(NSArray<NSString *> *)addressLines {
+- (void)setAddressLines:(nullable NSArray<NSString *> *)addressLines {
     [store sdl_setObject:addressLines forName:SDLNameAddressLines];
 }
 
-- (NSArray<NSString *> *)addressLines {
+- (nullable NSArray<NSString *> *)addressLines {
     return [store sdl_objectForName:SDLNameAddressLines];
 }
 
-- (void)setLocationDescription:(NSString *)locationDescription {
+- (void)setLocationDescription:(nullable NSString *)locationDescription {
     [store sdl_setObject:locationDescription forName:SDLNameLocationDescription];
 }
 
-- (NSString *)locationDescription {
+- (nullable NSString *)locationDescription {
     return [store sdl_objectForName:SDLNameLocationDescription];
 }
 
-- (void)setPhoneNumber:(NSString *)phoneNumber {
+- (void)setPhoneNumber:(nullable NSString *)phoneNumber {
     [store sdl_setObject:phoneNumber forName:SDLNamePhoneNumber];
 }
 
-- (NSString *)phoneNumber {
+- (nullable NSString *)phoneNumber {
     return [store sdl_objectForName:SDLNamePhoneNumber];
 }
 
-- (void)setLocationImage:(SDLImage *)locationImage {
+- (void)setLocationImage:(nullable SDLImage *)locationImage {
     [store sdl_setObject:locationImage forName:SDLNameLocationImage];
 }
 
-- (SDLImage *)locationImage {
+- (nullable SDLImage *)locationImage {
     return [store sdl_objectForName:SDLNameLocationImage ofClass:SDLImage.class];
 }
 
-- (void)setSearchAddress:(SDLOasisAddress *)searchAddress {
+- (void)setSearchAddress:(nullable SDLOasisAddress *)searchAddress {
     [store sdl_setObject:searchAddress forName:SDLNameSearchAddress];
 }
 
-- (SDLOasisAddress *)searchAddress {
+- (nullable SDLOasisAddress *)searchAddress {
     return [store sdl_objectForName:SDLNameSearchAddress ofClass:SDLOasisAddress.class];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLLockScreenStatusManager.h b/SmartDeviceLink/SDLLockScreenStatusManager.h
index 43c6d4fab..2a37b9d83 100644
--- a/SmartDeviceLink/SDLLockScreenStatusManager.h
+++ b/SmartDeviceLink/SDLLockScreenStatusManager.h
@@ -10,13 +10,16 @@
 
 @class SDLOnLockScreenStatus;
 
+NS_ASSUME_NONNULL_BEGIN
 
 @interface SDLLockScreenStatusManager : NSObject
 
 @property (assign, nonatomic) BOOL userSelected;
 @property (assign, nonatomic) BOOL driverDistracted;
-@property (strong, nonatomic) SDLHMILevel hmiLevel;
+@property (nullable, strong, nonatomic) SDLHMILevel hmiLevel;
 @property (strong, nonatomic, readonly) SDLLockScreenStatus lockScreenStatus;
 @property (strong, nonatomic, readonly) SDLOnLockScreenStatus *lockScreenStatusNotification;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLLockScreenStatusManager.m b/SmartDeviceLink/SDLLockScreenStatusManager.m
index 08742991d..87edc20d9 100644
--- a/SmartDeviceLink/SDLLockScreenStatusManager.m
+++ b/SmartDeviceLink/SDLLockScreenStatusManager.m
@@ -8,6 +8,7 @@
 #import "SDLLockScreenStatus.h"
 #import "SDLOnLockScreenStatus.h"
 
+NS_ASSUME_NONNULL_BEGIN
 
 @interface SDLLockScreenStatusManager ()
 
@@ -39,7 +40,7 @@
     _haveDriverDistractionStatus = YES;
 }
 
-- (void)setHmiLevel:(SDLHMILevel)hmiLevel {
+- (void)setHmiLevel:(nullable SDLHMILevel)hmiLevel {
     if (_hmiLevel != hmiLevel) {
         _hmiLevel = hmiLevel;
     }
@@ -92,3 +93,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLMenuParams.h b/SmartDeviceLink/SDLMenuParams.h
index 0c76a7e16..c5b0c81ff 100644
--- a/SmartDeviceLink/SDLMenuParams.h
+++ b/SmartDeviceLink/SDLMenuParams.h
@@ -9,6 +9,9 @@
  *
  * @since SDL 1.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLMenuParams : SDLRPCStruct
 
 - (instancetype)initWithMenuName:(NSString *)menuName;
@@ -21,7 +24,7 @@
  *
  * Optional, Integer, 0 - 2,000,000,000
  */
-@property (strong) NSNumber<SDLInt> *parentID;
+@property (nullable, strong, nonatomic) NSNumber<SDLInt> *parentID;
 
 /**
  * @abstract The position within the items of the parent Command Menu
@@ -35,13 +38,15 @@
  *
  * Optional, Integer, 0 - 1000
  */
-@property (strong) NSNumber<SDLInt> *position;
+@property (nullable, strong, nonatomic) NSNumber<SDLInt> *position;
 
 /**
  * @abstract the menu name which appears in menu, representing this command
  * 
  * Required, max length 500 characters
  */
-@property (strong) NSString *menuName;
+@property (strong, nonatomic) NSString *menuName;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLMenuParams.m b/SmartDeviceLink/SDLMenuParams.m
index 7b41410ce..89531b02f 100644
--- a/SmartDeviceLink/SDLMenuParams.m
+++ b/SmartDeviceLink/SDLMenuParams.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLMenuParams
 
 - (instancetype)initWithMenuName:(NSString *)menuName parentId:(UInt32)parentId position:(UInt16)position {
@@ -32,19 +34,19 @@
     return self;
 }
 
-- (void)setParentID:(NSNumber<SDLInt> *)parentID {
+- (void)setParentID:(nullable NSNumber<SDLInt> *)parentID {
     [store sdl_setObject:parentID forName:SDLNameParentId];
 }
 
-- (NSNumber<SDLInt> *)parentID {
+- (nullable NSNumber<SDLInt> *)parentID {
     return [store sdl_objectForName:SDLNameParentId];
 }
 
-- (void)setPosition:(NSNumber<SDLInt> *)position {
+- (void)setPosition:(nullable NSNumber<SDLInt> *)position {
     [store sdl_setObject:position forName:SDLNamePosition];
 }
 
-- (NSNumber<SDLInt> *)position {
+- (nullable NSNumber<SDLInt> *)position {
     return [store sdl_objectForName:SDLNamePosition];
 }
 
@@ -57,3 +59,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLMyKey.h b/SmartDeviceLink/SDLMyKey.h
index 30c1d490a..1100d4990 100644
--- a/SmartDeviceLink/SDLMyKey.h
+++ b/SmartDeviceLink/SDLMyKey.h
@@ -5,9 +5,12 @@
 
 #import "SDLVehicleDataStatus.h"
 
+NS_ASSUME_NONNULL_BEGIN
 
 @interface SDLMyKey : SDLRPCStruct
 
-@property (strong) SDLVehicleDataStatus e911Override;
+@property (strong, nonatomic) SDLVehicleDataStatus e911Override;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLMyKey.m b/SmartDeviceLink/SDLMyKey.m
index 7c81f3a4b..fc7f730f7 100644
--- a/SmartDeviceLink/SDLMyKey.m
+++ b/SmartDeviceLink/SDLMyKey.m
@@ -7,6 +7,8 @@
 #import "SDLNames.h"
 #import "SDLVehicleDataStatus.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLMyKey
 
 - (void)setE911Override:(SDLVehicleDataStatus)e911Override {
@@ -18,3 +20,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLNames.h b/SmartDeviceLink/SDLNames.h
index f13ecb179..10cc8c0f3 100644
--- a/SmartDeviceLink/SDLNames.h
+++ b/SmartDeviceLink/SDLNames.h
@@ -4,6 +4,8 @@
 #import <Foundation/Foundation.h>
 #import "SDLMacros.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 typedef NSString* SDLName SDL_SWIFT_ENUM;
 
 extern SDLName const SDLNameAccelerationPedalPosition;
@@ -441,3 +443,5 @@ extern SDLName const SDLNameWiperStatus;
 extern SDLName const SDLNameX;
 extern SDLName const SDLNameY;
 extern SDLName const SDLNameYear;
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLNames.m b/SmartDeviceLink/SDLNames.m
index 756c2ffce..c33df5b44 100644
--- a/SmartDeviceLink/SDLNames.m
+++ b/SmartDeviceLink/SDLNames.m
@@ -4,6 +4,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 SDLName const SDLNameAccelerationPedalPosition = @"accPedalPosition";
 SDLName const SDLNameActual = @"actual";
 SDLName const SDLNameAddCommand = @"AddCommand";
@@ -439,3 +441,5 @@ SDLName const SDLNameWiperStatus = @"wiperStatus";
 SDLName const SDLNameX = @"x";
 SDLName const SDLNameY = @"y";
 SDLName const SDLNameYear = @"year";
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLOasisAddress.h b/SmartDeviceLink/SDLOasisAddress.h
index 17bb00af6..d2a463264 100644
--- a/SmartDeviceLink/SDLOasisAddress.h
+++ b/SmartDeviceLink/SDLOasisAddress.h
@@ -3,73 +3,77 @@
 
 #import "SDLRPCStruct.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLOasisAddress : SDLRPCStruct
 
-- (instancetype)initWithSubThoroughfare:(NSString *)subThoroughfare thoroughfare:(NSString *)thoroughfare locality:(NSString *)locality administrativeArea:(NSString *)administrativeArea postalCode:(NSString *)postalCode countryCode:(NSString *)countryCode;
+- (instancetype)initWithSubThoroughfare:(nullable NSString *)subThoroughfare thoroughfare:(nullable NSString *)thoroughfare locality:(nullable NSString *)locality administrativeArea:(nullable NSString *)administrativeArea postalCode:(nullable NSString *)postalCode countryCode:(nullable NSString *)countryCode;
 
-- (instancetype)initWithSubThoroughfare:(NSString *)subThoroughfare thoroughfare:(NSString *)thoroughfare locality:(NSString *)locality administrativeArea:(NSString *)administrativeArea postalCode:(NSString *)postalCode countryCode:(NSString *)countryCode countryName:(NSString *)countryName subAdministrativeArea:(NSString *)subAdministrativeArea subLocality:(NSString *)subLocality;
+- (instancetype)initWithSubThoroughfare:(nullable NSString *)subThoroughfare thoroughfare:(nullable NSString *)thoroughfare locality:(nullable NSString *)locality administrativeArea:(nullable NSString *)administrativeArea postalCode:(nullable NSString *)postalCode countryCode:(nullable NSString *)countryCode countryName:(nullable NSString *)countryName subAdministrativeArea:(nullable NSString *)subAdministrativeArea subLocality:(nullable NSString *)subLocality;
 
 /**
  * @abstract Name of the country (localized)
  *
  * Optional, max length = 200
  */
-@property (copy, nonatomic) NSString *countryName;
+@property (nullable, copy, nonatomic) NSString *countryName;
 
 /**
  * @abstract countryCode of the country(ISO 3166-2)
  *
  * Optional, max length = 200
  */
-@property (copy, nonatomic) NSString *countryCode;
+@property (nullable, copy, nonatomic) NSString *countryCode;
 
 /**
  * @abstract postalCode of location (PLZ, ZIP, PIN, CAP etc.)
  *
  * Optional, max length = 200
  */
-@property (copy, nonatomic) NSString *postalCode;
+@property (nullable, copy, nonatomic) NSString *postalCode;
 
 /**
  * @abstract Portion of country (e.g. state)
  *
  * Optional, max length = 200
  */
-@property (copy, nonatomic) NSString *administrativeArea;
+@property (nullable, copy, nonatomic) NSString *administrativeArea;
 
 /**
  * @abstract Portion of administrativeArea (e.g. county)
  *
  * Optional, max length = 200
  */
-@property (copy, nonatomic) NSString *subAdministrativeArea;
+@property (nullable, copy, nonatomic) NSString *subAdministrativeArea;
 
 /**
  * @abstract Hypernym for city/village
  *
  * Optional, max length = 200
  */
-@property (copy, nonatomic) NSString *locality;
+@property (nullable, copy, nonatomic) NSString *locality;
 
 /**
  * @abstract Hypernym for district
  *
  * Optional, max length = 200
  */
-@property (copy, nonatomic) NSString *subLocality;
+@property (nullable, copy, nonatomic) NSString *subLocality;
 
 /**
  * @abstract Hypernym for street, road etc.
  *
  * Optional, max length = 200
  */
-@property (copy, nonatomic) NSString *thoroughfare;
+@property (nullable, copy, nonatomic) NSString *thoroughfare;
 
 /**
  * @abstract Portion of thoroughfare (e.g. house number)
  *
  * Optional, max length = 200
  */
-@property (copy, nonatomic) NSString *subThoroughfare;
+@property (nullable, copy, nonatomic) NSString *subThoroughfare;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLOasisAddress.m b/SmartDeviceLink/SDLOasisAddress.m
index 989af83da..97bfbe8cf 100644
--- a/SmartDeviceLink/SDLOasisAddress.m
+++ b/SmartDeviceLink/SDLOasisAddress.m
@@ -6,13 +6,15 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLOasisAddress
 
-- (instancetype)initWithSubThoroughfare:(NSString *)subThoroughfare thoroughfare:(NSString *)thoroughfare locality:(NSString *)locality administrativeArea:(NSString *)administrativeArea postalCode:(NSString *)postalCode countryCode:(NSString *)countryCode {
+- (instancetype)initWithSubThoroughfare:(nullable NSString *)subThoroughfare thoroughfare:(nullable NSString *)thoroughfare locality:(nullable NSString *)locality administrativeArea:(nullable NSString *)administrativeArea postalCode:(nullable NSString *)postalCode countryCode:(nullable NSString *)countryCode {
     return [self initWithSubThoroughfare:subThoroughfare thoroughfare:thoroughfare locality:locality administrativeArea:administrativeArea postalCode:postalCode countryCode:countryCode countryName:nil subAdministrativeArea:nil subLocality:nil];
 }
 
-- (instancetype)initWithSubThoroughfare:(NSString *)subThoroughfare thoroughfare:(NSString *)thoroughfare locality:(NSString *)locality administrativeArea:(NSString *)administrativeArea postalCode:(NSString *)postalCode countryCode:(NSString *)countryCode countryName:(NSString *)countryName subAdministrativeArea:(NSString *)subAdministrativeArea subLocality:(NSString *)subLocality {
+- (instancetype)initWithSubThoroughfare:(nullable NSString *)subThoroughfare thoroughfare:(nullable NSString *)thoroughfare locality:(nullable NSString *)locality administrativeArea:(nullable NSString *)administrativeArea postalCode:(nullable NSString *)postalCode countryCode:(nullable NSString *)countryCode countryName:(nullable NSString *)countryName subAdministrativeArea:(nullable NSString *)subAdministrativeArea subLocality:(nullable NSString *)subLocality {
     self = [self init];
     if (!self) {
         return nil;
@@ -31,77 +33,78 @@
     return self;
 }
 
-
-- (void)setCountryName:(NSString *)countryName {
+- (void)setCountryName:(nullable NSString *)countryName {
     [store sdl_setObject:countryName forName:SDLNameCountryName];
 }
 
-- (NSString *)countryName {
+- (nullable NSString *)countryName {
     return [store sdl_objectForName:SDLNameCountryName];
 }
 
-- (void)setCountryCode:(NSString *)countryCode {
+- (void)setCountryCode:(nullable NSString *)countryCode {
     [store sdl_setObject:countryCode forName:SDLNameCountryCode];
 }
 
-- (NSString *)countryCode {
+- (nullable NSString *)countryCode {
     return [store sdl_objectForName:SDLNameCountryCode];
 }
 
-- (void)setPostalCode:(NSString *)postalCode {
+- (void)setPostalCode:(nullable NSString *)postalCode {
     [store sdl_setObject:postalCode forName:SDLNamePostalCode];
 }
 
-- (NSString *)postalCode {
+- (nullable NSString *)postalCode {
     return [store sdl_objectForName:SDLNamePostalCode];
 }
 
-- (void)setAdministrativeArea:(NSString *)administrativeArea {
+- (void)setAdministrativeArea:(nullable NSString *)administrativeArea {
     [store sdl_setObject:administrativeArea forName:SDLNameAdministrativeArea];
 }
 
-- (NSString *)administrativeArea {
+- (nullable NSString *)administrativeArea {
     return [store sdl_objectForName:SDLNameAdministrativeArea];
 }
 
-- (void)setSubAdministrativeArea:(NSString *)subAdministrativeArea {
+- (void)setSubAdministrativeArea:(nullable NSString *)subAdministrativeArea {
     [store sdl_setObject:subAdministrativeArea forName:SDLNameSubAdministrativeArea];
 }
 
-- (NSString *)subAdministrativeArea {
+- (nullable NSString *)subAdministrativeArea {
     return [store sdl_objectForName:SDLNameSubAdministrativeArea];
 }
 
-- (void)setLocality:(NSString *)locality {
+- (void)setLocality:(nullable NSString *)locality {
     [store sdl_setObject:locality forName:SDLNameLocality];
 }
 
-- (NSString *)locality {
+- (nullable NSString *)locality {
     return [store sdl_objectForName:SDLNameLocality];
 }
 
-- (void)setSubLocality:(NSString *)subLocality {
+- (void)setSubLocality:(nullable NSString *)subLocality {
     [store sdl_setObject:subLocality forName:SDLNameSubLocality];
 }
 
-- (NSString *)subLocality {
+- (nullable NSString *)subLocality {
     return [store sdl_objectForName:SDLNameSubLocality];
 }
 
-- (void)setThoroughfare:(NSString *)thoroughfare {
+- (void)setThoroughfare:(nullable NSString *)thoroughfare {
     [store sdl_setObject:thoroughfare forName:SDLNameThoroughfare];
 }
 
-- (NSString *)thoroughfare {
+- (nullable NSString *)thoroughfare {
     return [store sdl_objectForName:SDLNameThoroughfare];
 }
 
-- (void)setSubThoroughfare:(NSString *)subThoroughfare {
+- (void)setSubThoroughfare:(nullable NSString *)subThoroughfare {
     [store sdl_setObject:subThoroughfare forName:SDLNameSubThoroughfare];
 }
 
-- (NSString *)subThoroughfare {
+- (nullable NSString *)subThoroughfare {
     return [store sdl_objectForName:SDLNameSubThoroughfare];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLObjectWithPriority.h b/SmartDeviceLink/SDLObjectWithPriority.h
index 334139d5f..848773f05 100644
--- a/SmartDeviceLink/SDLObjectWithPriority.h
+++ b/SmartDeviceLink/SDLObjectWithPriority.h
@@ -5,14 +5,17 @@
 
 #import <Foundation/Foundation.h>
 
+NS_ASSUME_NONNULL_BEGIN
 
 @interface SDLObjectWithPriority : NSObject
 
-@property (strong) id object;
-@property (assign) NSInteger priority;
+@property (nullable, strong, nonatomic) id object;
+@property (assign, nonatomic) NSInteger priority;
 
-- (instancetype)initWithObject:(id)object priority:(NSInteger)priority NS_DESIGNATED_INITIALIZER;
+- (instancetype)initWithObject:(nullable id)object priority:(NSInteger)priority NS_DESIGNATED_INITIALIZER;
 
-+ (instancetype)objectWithObject:(id)object priority:(NSInteger)priority;
++ (instancetype)objectWithObject:(nullable id)object priority:(NSInteger)priority;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLObjectWithPriority.m b/SmartDeviceLink/SDLObjectWithPriority.m
index 4dd72091e..6c8d72878 100644
--- a/SmartDeviceLink/SDLObjectWithPriority.m
+++ b/SmartDeviceLink/SDLObjectWithPriority.m
@@ -5,10 +5,11 @@
 
 #import "SDLObjectWithPriority.h"
 
+NS_ASSUME_NONNULL_BEGIN
 
 @implementation SDLObjectWithPriority
 
-- (instancetype)initWithObject:(id)object priority:(NSInteger)priority {
+- (instancetype)initWithObject:(nullable id)object priority:(NSInteger)priority {
     self = [super init];
     if (self == nil) {
         return nil;
@@ -24,8 +25,10 @@
     return [self initWithObject:nil priority:NSIntegerMax];
 }
 
-+ (instancetype)objectWithObject:(id)object priority:(NSInteger)priority {
++ (instancetype)objectWithObject:(nullable id)object priority:(NSInteger)priority {
     return [[self alloc] initWithObject:object priority:priority];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLOnAppInterfaceUnregistered.h b/SmartDeviceLink/SDLOnAppInterfaceUnregistered.h
index 5da94fb56..7e18b858a 100644
--- a/SmartDeviceLink/SDLOnAppInterfaceUnregistered.h
+++ b/SmartDeviceLink/SDLOnAppInterfaceUnregistered.h
@@ -14,11 +14,16 @@
  * @since SDL 1.0
  * @see SDLRegisterAppInterface
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLOnAppInterfaceUnregistered : SDLRPCNotification
 
 /**
  * @abstract The reason application's interface was terminated
  */
-@property (strong) SDLAppInterfaceUnregisteredReason reason;
+@property (strong, nonatomic) SDLAppInterfaceUnregisteredReason reason;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLOnAppInterfaceUnregistered.m b/SmartDeviceLink/SDLOnAppInterfaceUnregistered.m
index ea5bca870..a38ac0738 100644
--- a/SmartDeviceLink/SDLOnAppInterfaceUnregistered.m
+++ b/SmartDeviceLink/SDLOnAppInterfaceUnregistered.m
@@ -6,6 +6,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLOnAppInterfaceUnregistered
 
 - (instancetype)init {
@@ -23,3 +25,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLOnAudioPassThru.h b/SmartDeviceLink/SDLOnAudioPassThru.h
index 1f9c5d74b..4fc9d9e08 100644
--- a/SmartDeviceLink/SDLOnAudioPassThru.h
+++ b/SmartDeviceLink/SDLOnAudioPassThru.h
@@ -23,6 +23,11 @@
  * </ul>
  * </ul>
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLOnAudioPassThru : SDLRPCNotification
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLOnAudioPassThru.m b/SmartDeviceLink/SDLOnAudioPassThru.m
index 9e88bc4b7..2ab8fefc4 100644
--- a/SmartDeviceLink/SDLOnAudioPassThru.m
+++ b/SmartDeviceLink/SDLOnAudioPassThru.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLOnAudioPassThru
 
 - (instancetype)init {
@@ -16,3 +18,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLOnButtonEvent.h b/SmartDeviceLink/SDLOnButtonEvent.h
index a4c380608..f4b65d95d 100644
--- a/SmartDeviceLink/SDLOnButtonEvent.h
+++ b/SmartDeviceLink/SDLOnButtonEvent.h
@@ -43,17 +43,20 @@
  *
  * @since SDL 1.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLOnButtonEvent : SDLRPCNotification
 
 /**
  * @abstract The name of the button
  */
-@property (strong) SDLButtonName buttonName;
+@property (strong, nonatomic) SDLButtonName buttonName;
 
 /**
  * @abstract Indicates whether this is an UP or DOWN event
  */
-@property (strong) SDLButtonEventMode buttonEventMode;
+@property (strong, nonatomic) SDLButtonEventMode buttonEventMode;
 
 /**
  * @abstract If ButtonName is "CUSTOM_BUTTON", this references the integer ID passed by a custom button. (e.g. softButton ID)
@@ -62,6 +65,8 @@
  *
  * Optional, Integer, 0 - 65536
  */
-@property (strong) NSNumber<SDLInt> *customButtonID;
+@property (nullable, strong, nonatomic) NSNumber<SDLInt> *customButtonID;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLOnButtonEvent.m b/SmartDeviceLink/SDLOnButtonEvent.m
index e3b7ed3ca..4d65422a8 100644
--- a/SmartDeviceLink/SDLOnButtonEvent.m
+++ b/SmartDeviceLink/SDLOnButtonEvent.m
@@ -6,6 +6,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLOnButtonEvent
 
 - (instancetype)init {
@@ -32,12 +34,14 @@
     return (SDLButtonEventMode)obj;
 }
 
-- (void)setCustomButtonID:(NSNumber<SDLInt> *)customButtonID {
+- (void)setCustomButtonID:(nullable NSNumber<SDLInt> *)customButtonID {
     [parameters sdl_setObject:customButtonID forName:SDLNameCustomButtonId];
 }
 
-- (NSNumber<SDLInt> *)customButtonID {
+- (nullable NSNumber<SDLInt> *)customButtonID {
     return [parameters sdl_objectForName:SDLNameCustomButtonId];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLOnButtonPress.h b/SmartDeviceLink/SDLOnButtonPress.h
index 7aee6a4e4..1c8381114 100644
--- a/SmartDeviceLink/SDLOnButtonPress.h
+++ b/SmartDeviceLink/SDLOnButtonPress.h
@@ -48,6 +48,9 @@
  *
  * @since SDL 1.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLOnButtonPress : SDLRPCNotification
 
 /**
@@ -57,7 +60,7 @@
  *
  * Required
  */
-@property (strong) SDLButtonName buttonName;
+@property (strong, nonatomic) SDLButtonName buttonName;
 
 /**
  * @abstract Indicates whether this is a LONG or SHORT button press event
@@ -66,7 +69,7 @@
  *
  * Required
  */
-@property (strong) SDLButtonPressMode buttonPressMode;
+@property (strong, nonatomic) SDLButtonPressMode buttonPressMode;
 
 /**
  * @abstract If ButtonName is "CUSTOM_BUTTON", this references the integer ID passed by a custom button. (e.g. softButton ID)
@@ -75,6 +78,8 @@
  *
  * Optional, Integer 0 - 65536
  */
-@property (strong) NSNumber<SDLInt> *customButtonID;
+@property (nullable, strong, nonatomic) NSNumber<SDLInt> *customButtonID;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLOnButtonPress.m b/SmartDeviceLink/SDLOnButtonPress.m
index ec1530314..addeccfd8 100644
--- a/SmartDeviceLink/SDLOnButtonPress.m
+++ b/SmartDeviceLink/SDLOnButtonPress.m
@@ -6,6 +6,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLOnButtonPress
 
 - (instancetype)init {
@@ -32,12 +34,14 @@
     return (SDLButtonPressMode)obj;
 }
 
-- (void)setCustomButtonID:(NSNumber<SDLInt> *)customButtonID {
+- (void)setCustomButtonID:(nullable NSNumber<SDLInt> *)customButtonID {
     [parameters sdl_setObject:customButtonID forName:SDLNameCustomButtonId];
 }
 
-- (NSNumber<SDLInt> *)customButtonID {
+- (nullable NSNumber<SDLInt> *)customButtonID {
     return [parameters sdl_objectForName:SDLNameCustomButtonId];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLOnCommand.h b/SmartDeviceLink/SDLOnCommand.h
index fe52f29cc..0b685a486 100644
--- a/SmartDeviceLink/SDLOnCommand.h
+++ b/SmartDeviceLink/SDLOnCommand.h
@@ -14,16 +14,21 @@
  * @since SDL 1.0
  * @see SDLAddCommand SDLDeleteCommand SDLDeleteSubMenu
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLOnCommand : SDLRPCNotification
 
 /**
  * @abstract The command ID of the command the user selected. This is the command ID value provided by the application in the <i>SDLAddCommand</i> operation that created the command.
  */
-@property (strong) NSNumber<SDLInt> *cmdID;
+@property (strong, nonatomic) NSNumber<SDLInt> *cmdID;
 
 /**
  * @abstract Indicates whether command was selected via voice or via a menu selection (using the OK button).
  */
-@property (strong) SDLTriggerSource triggerSource;
+@property (strong, nonatomic) SDLTriggerSource triggerSource;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLOnCommand.m b/SmartDeviceLink/SDLOnCommand.m
index e5de51ffb..f1d547852 100644
--- a/SmartDeviceLink/SDLOnCommand.m
+++ b/SmartDeviceLink/SDLOnCommand.m
@@ -6,6 +6,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLOnCommand
 
 - (instancetype)init {
@@ -32,3 +34,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLOnDriverDistraction.h b/SmartDeviceLink/SDLOnDriverDistraction.h
index ef6d0ab2f..7a0b4e163 100644
--- a/SmartDeviceLink/SDLOnDriverDistraction.h
+++ b/SmartDeviceLink/SDLOnDriverDistraction.h
@@ -22,11 +22,16 @@
  *
  * @since SDL 1.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLOnDriverDistraction : SDLRPCNotification
 
 /**
  * @abstract The driver distraction state (i.e. whether driver distraction rules are in effect, or not)
  */
-@property (strong) SDLDriverDistractionState state;
+@property (strong, nonatomic) SDLDriverDistractionState state;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLOnDriverDistraction.m b/SmartDeviceLink/SDLOnDriverDistraction.m
index f43e6c106..cba06de2e 100644
--- a/SmartDeviceLink/SDLOnDriverDistraction.m
+++ b/SmartDeviceLink/SDLOnDriverDistraction.m
@@ -7,6 +7,8 @@
 #import "SDLNames.h"
 #import "SDLDriverDistractionState.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLOnDriverDistraction
 
 - (instancetype)init {
@@ -25,3 +27,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLOnEncodedSyncPData.h b/SmartDeviceLink/SDLOnEncodedSyncPData.h
index d0a2b218c..9bcbdae45 100644
--- a/SmartDeviceLink/SDLOnEncodedSyncPData.h
+++ b/SmartDeviceLink/SDLOnEncodedSyncPData.h
@@ -3,11 +3,14 @@
 
 #import "SDLRPCNotification.h"
 
+NS_ASSUME_NONNULL_BEGIN
 
 @interface SDLOnEncodedSyncPData : SDLRPCNotification
 
-@property (strong) NSMutableArray<NSString *> *data;
-@property (strong) NSString *URL;
-@property (strong) NSNumber<SDLInt> *Timeout;
+@property (strong, nonatomic) NSMutableArray<NSString *> *data;
+@property (nullable, strong, nonatomic) NSString *URL;
+@property (nullable, strong, nonatomic) NSNumber<SDLInt> *Timeout;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLOnEncodedSyncPData.m b/SmartDeviceLink/SDLOnEncodedSyncPData.m
index caf473c1a..3a8eefe78 100644
--- a/SmartDeviceLink/SDLOnEncodedSyncPData.m
+++ b/SmartDeviceLink/SDLOnEncodedSyncPData.m
@@ -6,6 +6,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLOnEncodedSyncPData
 
 - (instancetype)init {
@@ -22,20 +24,22 @@
     return [parameters sdl_objectForName:SDLNameData];
 }
 
-- (void)setURL:(NSString *)URL {
+- (void)setURL:(nullable NSString *)URL {
     [parameters sdl_setObject:URL forName:SDLNameURLUppercase];
 }
 
-- (NSString *)URL {
+- (nullable NSString *)URL {
     return [parameters sdl_objectForName:SDLNameURLUppercase];
 }
 
-- (void)setTimeout:(NSNumber<SDLInt> *)Timeout {
+- (void)setTimeout:(nullable NSNumber<SDLInt> *)Timeout {
     [parameters sdl_setObject:Timeout forName:SDLNameTimeoutCapitalized];
 }
 
-- (NSNumber<SDLInt> *)Timeout {
+- (nullable NSNumber<SDLInt> *)Timeout {
     return [parameters sdl_objectForName:SDLNameTimeoutCapitalized];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLOnHMIStatus.h b/SmartDeviceLink/SDLOnHMIStatus.h
index e7dbe6241..10ae21948 100644
--- a/SmartDeviceLink/SDLOnHMIStatus.h
+++ b/SmartDeviceLink/SDLOnHMIStatus.h
@@ -22,24 +22,29 @@
  * 
  * @since SDL 1.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLOnHMIStatus : SDLRPCNotification
 
 /**
  * @abstract SDLHMILevel in effect for the application
  */
-@property (strong) SDLHMILevel hmiLevel;
+@property (strong, nonatomic) SDLHMILevel hmiLevel;
 
 /**
  * @abstract Current state of audio streaming for the application. When this parameter has a value of NOT_AUDIBLE, the application must stop streaming audio to SDL.
  *
  * Informs app whether any currently streaming audio is audible to user (AUDIBLE) or not (NOT_AUDIBLE). A value of NOT_AUDIBLE means that either the application's audio will not be audible to the user, or that the application's audio should not be audible to the user (i.e. some other application on the mobile device may be streaming audio and the application's audio would be blended with that other audio).
  */
-@property (strong) SDLAudioStreamingState audioStreamingState;
+@property (strong, nonatomic) SDLAudioStreamingState audioStreamingState;
 
 /**
  * @abstract the System Context
  * @discussion whether a user-initiated interaction is in-progress (VRSESSION or MENU), or not (MAIN)
  */
-@property (strong) SDLSystemContext systemContext;
+@property (strong, nonatomic) SDLSystemContext systemContext;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLOnHMIStatus.m b/SmartDeviceLink/SDLOnHMIStatus.m
index 4f71a4300..6240ec9c2 100644
--- a/SmartDeviceLink/SDLOnHMIStatus.m
+++ b/SmartDeviceLink/SDLOnHMIStatus.m
@@ -9,6 +9,8 @@
 #import "SDLNames.h"
 #import "SDLSystemContext.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLOnHMIStatus
 
 - (instancetype)init {
@@ -45,3 +47,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLOnHashChange.h b/SmartDeviceLink/SDLOnHashChange.h
index e339444e9..59dd0f0d0 100644
--- a/SmartDeviceLink/SDLOnHashChange.h
+++ b/SmartDeviceLink/SDLOnHashChange.h
@@ -4,8 +4,12 @@
 
 #import "SDLRPCNotification.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLOnHashChange : SDLRPCNotification
 
-@property (strong) NSString *hashID;
+@property (strong, nonatomic) NSString *hashID;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLOnHashChange.m b/SmartDeviceLink/SDLOnHashChange.m
index 186873a8d..f3fb70731 100644
--- a/SmartDeviceLink/SDLOnHashChange.m
+++ b/SmartDeviceLink/SDLOnHashChange.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLOnHashChange
 
 - (instancetype)init {
@@ -24,3 +26,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLOnKeyboardInput.h b/SmartDeviceLink/SDLOnKeyboardInput.h
index d3c49a85d..38c4989ef 100644
--- a/SmartDeviceLink/SDLOnKeyboardInput.h
+++ b/SmartDeviceLink/SDLOnKeyboardInput.h
@@ -5,10 +5,13 @@
 
 #import "SDLKeyboardEvent.h"
 
+NS_ASSUME_NONNULL_BEGIN
 
 @interface SDLOnKeyboardInput : SDLRPCNotification
 
-@property (strong) SDLKeyboardEvent event;
-@property (strong) NSString *data;
+@property (strong, nonatomic) SDLKeyboardEvent event;
+@property (nullable, strong, nonatomic) NSString *data;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLOnKeyboardInput.m b/SmartDeviceLink/SDLOnKeyboardInput.m
index cfa35eedc..a6bd02295 100644
--- a/SmartDeviceLink/SDLOnKeyboardInput.m
+++ b/SmartDeviceLink/SDLOnKeyboardInput.m
@@ -6,6 +6,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLOnKeyboardInput
 
 - (instancetype)init {
@@ -23,12 +25,14 @@
     return (SDLKeyboardEvent)obj;
 }
 
-- (void)setData:(NSString *)data {
+- (void)setData:(nullable NSString *)data {
     [parameters sdl_setObject:data forName:SDLNameData];
 }
 
-- (NSString *)data {
+- (nullable NSString *)data {
     return [parameters sdl_objectForName:SDLNameData];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLOnLanguageChange.h b/SmartDeviceLink/SDLOnLanguageChange.h
index f5bae80d1..4937c70fd 100644
--- a/SmartDeviceLink/SDLOnLanguageChange.h
+++ b/SmartDeviceLink/SDLOnLanguageChange.h
@@ -11,16 +11,21 @@
  *
  * @since SDL 2.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLOnLanguageChange : SDLRPCNotification
 
 /**
  * @abstract Current SDL voice engine (VR+TTS) language
  */
-@property (strong) SDLLanguage language;
+@property (strong, nonatomic) SDLLanguage language;
 
 /**
  * @abstract Current display language
  */
-@property (strong) SDLLanguage hmiDisplayLanguage;
+@property (strong, nonatomic) SDLLanguage hmiDisplayLanguage;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLOnLanguageChange.m b/SmartDeviceLink/SDLOnLanguageChange.m
index fea4805fa..419875f73 100644
--- a/SmartDeviceLink/SDLOnLanguageChange.m
+++ b/SmartDeviceLink/SDLOnLanguageChange.m
@@ -7,6 +7,8 @@
 #import "SDLLanguage.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLOnLanguageChange
 
 - (instancetype)init {
@@ -35,3 +37,5 @@
 
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLOnLockScreenStatus.h b/SmartDeviceLink/SDLOnLockScreenStatus.h
index c0b0896a8..830cd223f 100644
--- a/SmartDeviceLink/SDLOnLockScreenStatus.h
+++ b/SmartDeviceLink/SDLOnLockScreenStatus.h
@@ -17,28 +17,33 @@
  *	For simplicity, the OnLockScreenStatus RPC will be provided via the onOnLockScreenNotification call back. The call back will include the LockScreenStatus enum which indicates if the lockscreen is required, optional or not required.
  *	The call back also includes details regarding the current HMI_Status level, driver distraction status and user selection status of the application.
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLOnLockScreenStatus : SDLRPCNotification
 
 /**
  * <p>Get the current driver distraction status(i.e. whether driver distraction rules are in effect, or not)</p>
  * @return String
  */
-@property (strong) NSNumber<SDLBool> *driverDistractionStatus;
+@property (strong, nonatomic) NSNumber<SDLBool> *driverDistractionStatus;
 /**
  * <p>Get user selection status for the application (has the app been selected via hmi or voice command)</p>
  * @return Boolean the current user selection status
  */
 
-@property (strong) NSNumber<SDLBool> *userSelected;
+@property (strong, nonatomic) NSNumber<SDLBool> *userSelected;
 /**
  * <p>Get the {@linkplain LockScreenStatus} enumeration, indicating if the lockscreen should be required, optional or off </p>
  * @return {@linkplain LockScreenStatus}
  */
-@property (strong) SDLLockScreenStatus lockScreenStatus;
+@property (strong, nonatomic) SDLLockScreenStatus lockScreenStatus;
 /**
  * <p>Get HMILevel in effect for the application</p>
  * @return {@linkplain HMILevel} the current HMI Level in effect for the application
  */
-@property (strong) SDLHMILevel hmiLevel;
+@property (strong, nonatomic) SDLHMILevel hmiLevel;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLOnLockScreenStatus.m b/SmartDeviceLink/SDLOnLockScreenStatus.m
index 94b26aac9..77b8c5848 100644
--- a/SmartDeviceLink/SDLOnLockScreenStatus.m
+++ b/SmartDeviceLink/SDLOnLockScreenStatus.m
@@ -9,6 +9,8 @@
 #import "SDLHMILevel.h"
 #import "SDLLockScreenStatus.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLOnLockScreenStatus
 
 - (instancetype)init {
@@ -50,3 +52,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLOnPermissionsChange.h b/SmartDeviceLink/SDLOnPermissionsChange.h
index b32d6cbe6..daec5ec66 100644
--- a/SmartDeviceLink/SDLOnPermissionsChange.h
+++ b/SmartDeviceLink/SDLOnPermissionsChange.h
@@ -10,6 +10,9 @@
  *
  * @since SDL 2.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLOnPermissionsChange : SDLRPCNotification
 
 /**
@@ -19,6 +22,8 @@
  *
  * @see SDLPermissionItem
  */
-@property (strong) NSMutableArray<SDLPermissionItem *> *permissionItem;
+@property (strong, nonatomic) NSMutableArray<SDLPermissionItem *> *permissionItem;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLOnPermissionsChange.m b/SmartDeviceLink/SDLOnPermissionsChange.m
index 554c9eeb7..d6350f2b2 100644
--- a/SmartDeviceLink/SDLOnPermissionsChange.m
+++ b/SmartDeviceLink/SDLOnPermissionsChange.m
@@ -7,6 +7,8 @@
 #import "SDLNames.h"
 #import "SDLPermissionItem.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLOnPermissionsChange
 
 - (instancetype)init {
@@ -33,3 +35,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLOnSyncPData.h b/SmartDeviceLink/SDLOnSyncPData.h
index a7dd55d4d..cf2e1af13 100644
--- a/SmartDeviceLink/SDLOnSyncPData.h
+++ b/SmartDeviceLink/SDLOnSyncPData.h
@@ -4,9 +4,13 @@
 
 #import "SDLRPCNotification.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLOnSyncPData : SDLRPCNotification
 
-@property (strong) NSString *URL;
-@property (strong) NSNumber<SDLInt> *Timeout;
+@property (nullable, strong, nonatomic) NSString *URL;
+@property (nullable, strong, nonatomic) NSNumber<SDLInt> *Timeout;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLOnSyncPData.m b/SmartDeviceLink/SDLOnSyncPData.m
index 2b9d4bd26..13446ab88 100644
--- a/SmartDeviceLink/SDLOnSyncPData.m
+++ b/SmartDeviceLink/SDLOnSyncPData.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLOnSyncPData
 
 - (instancetype)init {
@@ -15,20 +17,22 @@
     return self;
 }
 
-- (void)setURL:(NSString *)URL {
+- (void)setURL:(nullable NSString *)URL {
     [parameters sdl_setObject:URL forName:SDLNameURLUppercase];
 }
 
-- (NSString *)URL {
+- (nullable NSString *)URL {
     return [parameters sdl_objectForName:SDLNameURLUppercase];
 }
 
-- (void)setTimeout:(NSNumber<SDLInt> *)Timeout {
+- (void)setTimeout:(nullable NSNumber<SDLInt> *)Timeout {
     [parameters sdl_setObject:Timeout forName:SDLNameTimeoutCapitalized];
 }
 
-- (NSNumber<SDLInt> *)Timeout {
+- (nullable NSNumber<SDLInt> *)Timeout {
     return [parameters sdl_objectForName:SDLNameTimeoutCapitalized];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLOnSystemRequest.h b/SmartDeviceLink/SDLOnSystemRequest.h
index 3b09ed9fd..236cde278 100644
--- a/SmartDeviceLink/SDLOnSystemRequest.h
+++ b/SmartDeviceLink/SDLOnSystemRequest.h
@@ -6,14 +6,17 @@
 #import "SDLFileType.h"
 #import "SDLRequestType.h"
 
+NS_ASSUME_NONNULL_BEGIN
 
 @interface SDLOnSystemRequest : SDLRPCNotification
 
-@property (strong) SDLRequestType requestType;
-@property (strong) NSString *url;
-@property (strong) NSNumber<SDLInt> *timeout;
-@property (strong) SDLFileType fileType;
-@property (strong) NSNumber<SDLUInt> *offset;
-@property (strong) NSNumber<SDLUInt> *length;
+@property (strong, nonatomic) SDLRequestType requestType;
+@property (nullable, strong, nonatomic) NSString *url;
+@property (nullable, strong, nonatomic) NSNumber<SDLInt> *timeout;
+@property (nullable, strong, nonatomic) SDLFileType fileType;
+@property (nullable, strong, nonatomic) NSNumber<SDLUInt> *offset;
+@property (nullable, strong, nonatomic) NSNumber<SDLUInt> *length;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLOnSystemRequest.m b/SmartDeviceLink/SDLOnSystemRequest.m
index ce45a0142..30e58a1a9 100644
--- a/SmartDeviceLink/SDLOnSystemRequest.m
+++ b/SmartDeviceLink/SDLOnSystemRequest.m
@@ -6,6 +6,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLOnSystemRequest
 
 - (instancetype)init {
@@ -19,49 +21,49 @@
 }
 
 - (SDLRequestType)requestType {
-    NSObject *obj = [parameters sdl_objectForName:SDLNameRequestType];
-    return (SDLRequestType)obj;
+    return [parameters sdl_objectForName:SDLNameRequestType];
 }
 
-- (void)setUrl:(NSString *)url {
+- (void)setUrl:(nullable NSString *)url {
     [parameters sdl_setObject:url forName:SDLNameURL];
 }
 
-- (NSString *)url {
+- (nullable NSString *)url {
     return [parameters sdl_objectForName:SDLNameURL];
 }
 
-- (void)setTimeout:(NSNumber<SDLInt> *)timeout {
+- (void)setTimeout:(nullable NSNumber<SDLInt> *)timeout {
     [parameters sdl_setObject:timeout forName:SDLNameTimeout];
 }
 
-- (NSNumber<SDLInt> *)timeout {
+- (nullable NSNumber<SDLInt> *)timeout {
     return [parameters sdl_objectForName:SDLNameTimeout];
 }
 
-- (void)setFileType:(SDLFileType)fileType {
+- (void)setFileType:(nullable SDLFileType)fileType {
     [parameters sdl_setObject:fileType forName:SDLNameFileType];
 }
 
-- (SDLFileType)fileType {
-    NSObject *obj = [parameters sdl_objectForName:SDLNameFileType];
-    return (SDLFileType)obj;
+- (nullable SDLFileType)fileType {
+    return [parameters sdl_objectForName:SDLNameFileType];
 }
 
-- (void)setOffset:(NSNumber<SDLInt> *)offset {
+- (void)setOffset:(nullable NSNumber<SDLInt> *)offset {
     [parameters sdl_setObject:offset forName:SDLNameOffset];
 }
 
-- (NSNumber<SDLInt> *)offset {
+- (nullable NSNumber<SDLInt> *)offset {
     return [parameters sdl_objectForName:SDLNameOffset];
 }
 
-- (void)setLength:(NSNumber<SDLInt> *)length {
+- (void)setLength:(nullable NSNumber<SDLInt> *)length {
     [parameters sdl_setObject:length forName:SDLNameLength];
 }
 
-- (NSNumber<SDLInt> *)length {
+- (nullable NSNumber<SDLInt> *)length {
     return [parameters sdl_objectForName:SDLNameLength];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLOnTBTClientState.h b/SmartDeviceLink/SDLOnTBTClientState.h
index 29d8a50a6..33e9c37be 100644
--- a/SmartDeviceLink/SDLOnTBTClientState.h
+++ b/SmartDeviceLink/SDLOnTBTClientState.h
@@ -5,8 +5,12 @@
 
 #import "SDLTBTState.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLOnTBTClientState : SDLRPCNotification
 
-@property (strong) SDLTBTState state;
+@property (strong, nonatomic) SDLTBTState state;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLOnTBTClientState.m b/SmartDeviceLink/SDLOnTBTClientState.m
index 8a04eed45..41bc28f0d 100644
--- a/SmartDeviceLink/SDLOnTBTClientState.m
+++ b/SmartDeviceLink/SDLOnTBTClientState.m
@@ -6,6 +6,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLOnTBTClientState
 
 - (instancetype)init {
@@ -24,3 +26,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLOnTouchEvent.h b/SmartDeviceLink/SDLOnTouchEvent.h
index 7e6b00f7d..21b3e1c5b 100644
--- a/SmartDeviceLink/SDLOnTouchEvent.h
+++ b/SmartDeviceLink/SDLOnTouchEvent.h
@@ -7,9 +7,13 @@
 
 @class SDLTouchEvent;
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLOnTouchEvent : SDLRPCNotification
 
-@property (strong) SDLTouchType type;
-@property (strong) NSMutableArray<SDLTouchEvent *> *event;
+@property (strong, nonatomic) SDLTouchType type;
+@property (strong, nonatomic) NSMutableArray<SDLTouchEvent *> *event;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLOnTouchEvent.m b/SmartDeviceLink/SDLOnTouchEvent.m
index 76c90272c..e0fc56bb5 100644
--- a/SmartDeviceLink/SDLOnTouchEvent.m
+++ b/SmartDeviceLink/SDLOnTouchEvent.m
@@ -7,6 +7,8 @@
 #import "SDLNames.h"
 #import "SDLTouchEvent.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLOnTouchEvent
 
 - (instancetype)init {
@@ -42,3 +44,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLOnVehicleData.h b/SmartDeviceLink/SDLOnVehicleData.h
index 2e5bf3a13..6a8c4af78 100644
--- a/SmartDeviceLink/SDLOnVehicleData.h
+++ b/SmartDeviceLink/SDLOnVehicleData.h
@@ -26,112 +26,117 @@
  *
  * Since SmartDeviceLink 2.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLOnVehicleData : SDLRPCNotification
 
 /**
  * @abstract A SDLGPSData* value. See GPSData.
  */
-@property (strong) SDLGPSData *gps;
+@property (nullable, strong, nonatomic) SDLGPSData *gps;
 
 /**
  * @abstract The vehicle speed in kilometers per hour.
  */
-@property (strong) NSNumber<SDLFloat> *speed;
+@property (nullable, strong, nonatomic) NSNumber<SDLFloat> *speed;
 
 /**
  * @abstract The number of revolutions per minute of the engine.
  */
-@property (strong) NSNumber<SDLInt> *rpm;
+@property (nullable, strong, nonatomic) NSNumber<SDLInt> *rpm;
 
 /**
  * @abstract The fuel level in the tank (percentage)
  */
-@property (strong) NSNumber<SDLFloat> *fuelLevel;
+@property (nullable, strong, nonatomic) NSNumber<SDLFloat> *fuelLevel;
 
 /**
  * @abstract A SDLComponentVolumeStatus* value. The fuel level state.
  */
-@property (strong) SDLComponentVolumeStatus fuelLevel_State;
+@property (nullable, strong, nonatomic) SDLComponentVolumeStatus fuelLevel_State;
 
 /**
  * @abstract The instantaneous fuel consumption in microlitres.
  */
-@property (strong) NSNumber<SDLFloat> *instantFuelConsumption;
+@property (nullable, strong, nonatomic) NSNumber<SDLFloat> *instantFuelConsumption;
 
 /**
  * @abstract The external temperature in degrees celsius.
  */
-@property (strong) NSNumber<SDLFloat> *externalTemperature;
+@property (nullable, strong, nonatomic) NSNumber<SDLFloat> *externalTemperature;
 
 /**
  * @abstract The Vehicle Identification Number
  */
-@property (strong) NSString *vin;
+@property (nullable, strong, nonatomic) NSString *vin;
 
 /**
  * @abstract See PRNDL.
  */
-@property (strong) SDLPRNDL prndl;
+@property (nullable, strong, nonatomic) SDLPRNDL prndl;
 
 /**
  * @abstract A SDLTireStatus* value. See TireStatus.
  */
-@property (strong) SDLTireStatus *tirePressure;
+@property (nullable, strong, nonatomic) SDLTireStatus *tirePressure;
 
 /**
  * @abstract Odometer reading in km.
  */
-@property (strong) NSNumber<SDLInt> *odometer;
+@property (nullable, strong, nonatomic) NSNumber<SDLInt> *odometer;
 
 /**
  * @abstract A SDLBeltStatus* value. The status of the seat belts.
  */
-@property (strong) SDLBeltStatus *beltStatus;
+@property (nullable, strong, nonatomic) SDLBeltStatus *beltStatus;
 
 /**
  * @abstract A SDLBodyInformation* value. The body information including power modes.
  */
-@property (strong) SDLBodyInformation *bodyInformation;
+@property (nullable, strong, nonatomic) SDLBodyInformation *bodyInformation;
 
 /**
  * @abstract A SDLDeviceStatus* value. The device status including signal and battery strength.
  */
-@property (strong) SDLDeviceStatus *deviceStatus;
+@property (nullable, strong, nonatomic) SDLDeviceStatus *deviceStatus;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The status of the brake pedal.
  */
-@property (strong) SDLVehicleDataEventStatus driverBraking;
+@property (nullable, strong, nonatomic) SDLVehicleDataEventStatus driverBraking;
 
 /**
  * @abstract A SDLWiperStatus* value. The status of the wipers.
  */
-@property (strong) SDLWiperStatus wiperStatus;
+@property (nullable, strong, nonatomic) SDLWiperStatus wiperStatus;
 
 /**
  * @abstract A SDLHeadLampStatus* value. Status of the head lamps.
  */
-@property (strong) SDLHeadLampStatus *headLampStatus;
+@property (nullable, strong, nonatomic) SDLHeadLampStatus *headLampStatus;
 
 /**
  * @abstract Torque value for engine (in Nm) on non-diesel variants.
  */
-@property (strong) NSNumber<SDLFloat> *engineTorque;
+@property (nullable, strong, nonatomic) NSNumber<SDLFloat> *engineTorque;
 
 /**
  * @abstract Accelerator pedal position (percentage depressed)
  */
-@property (strong) NSNumber<SDLFloat> *accPedalPosition;
+@property (nullable, strong, nonatomic) NSNumber<SDLFloat> *accPedalPosition;
 
 /**
  * @abstract Current angle of the steering wheel (in deg)
  */
-@property (strong) NSNumber<SDLFloat> *steeringWheelAngle;
-@property (strong) SDLECallInfo *eCallInfo;
-@property (strong) SDLAirbagStatus *airbagStatus;
-@property (strong) SDLEmergencyEvent *emergencyEvent;
-@property (strong) SDLClusterModeStatus *clusterModeStatus;
-@property (strong) SDLMyKey *myKey;
+@property (nullable, strong, nonatomic) NSNumber<SDLFloat> *steeringWheelAngle;
+@property (nullable, strong, nonatomic) SDLECallInfo *eCallInfo;
+@property (nullable, strong, nonatomic) SDLAirbagStatus *airbagStatus;
+@property (nullable, strong, nonatomic) SDLEmergencyEvent *emergencyEvent;
+@property (nullable, strong, nonatomic) SDLClusterModeStatus *clusterModeStatus;
+@property (nullable, strong, nonatomic) SDLMyKey *myKey;
 
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLOnVehicleData.m b/SmartDeviceLink/SDLOnVehicleData.m
index 7e793489a..6f4e99521 100644
--- a/SmartDeviceLink/SDLOnVehicleData.m
+++ b/SmartDeviceLink/SDLOnVehicleData.m
@@ -17,6 +17,7 @@
 #import "SDLNames.h"
 #import "SDLTireStatus.h"
 
+NS_ASSUME_NONNULL_BEGIN
 
 @implementation SDLOnVehicleData
 
@@ -26,263 +27,207 @@
     return self;
 }
 
-- (void)setGps:(SDLGPSData *)gps {
+- (void)setGps:(nullable SDLGPSData *)gps {
     [parameters sdl_setObject:gps forName:SDLNameGPS];
 }
 
-- (SDLGPSData *)gps {
-    NSObject *obj = [parameters sdl_objectForName:SDLNameGPS];
-    if (obj == nil || [obj isKindOfClass:SDLGPSData.class]) {
-        return (SDLGPSData *)obj;
-    } else {
-        return [[SDLGPSData alloc] initWithDictionary:(NSDictionary *)obj];
-    }
+- (nullable SDLGPSData *)gps {
+    return [parameters sdl_objectForName:SDLNameGPS ofClass:SDLGPSData.class];
 }
 
-- (void)setSpeed:(NSNumber<SDLFloat> *)speed {
+- (void)setSpeed:(nullable NSNumber<SDLFloat> *)speed {
     [parameters sdl_setObject:speed forName:SDLNameSpeed];
 }
 
-- (NSNumber<SDLFloat> *)speed {
+- (nullable NSNumber<SDLFloat> *)speed {
     return [parameters sdl_objectForName:SDLNameSpeed];
 }
 
-- (void)setRpm:(NSNumber<SDLInt> *)rpm {
+- (void)setRpm:(nullable NSNumber<SDLInt> *)rpm {
     [parameters sdl_setObject:rpm forName:SDLNameRPM];
 }
 
-- (NSNumber<SDLInt> *)rpm {
+- (nullable NSNumber<SDLInt> *)rpm {
     return [parameters sdl_objectForName:SDLNameRPM];
 }
 
-- (void)setFuelLevel:(NSNumber<SDLFloat> *)fuelLevel {
+- (void)setFuelLevel:(nullable NSNumber<SDLFloat> *)fuelLevel {
     [parameters sdl_setObject:fuelLevel forName:SDLNameFuelLevel];
 }
 
-- (NSNumber<SDLFloat> *)fuelLevel {
+- (nullable NSNumber<SDLFloat> *)fuelLevel {
     return [parameters sdl_objectForName:SDLNameFuelLevel];
 }
 
-- (void)setFuelLevel_State:(SDLComponentVolumeStatus)fuelLevel_State {
+- (void)setFuelLevel_State:(nullable SDLComponentVolumeStatus)fuelLevel_State {
     [parameters sdl_setObject:fuelLevel_State forName:SDLNameFuelLevelState];
 }
 
-- (SDLComponentVolumeStatus)fuelLevel_State {
-    NSObject *obj = [parameters sdl_objectForName:SDLNameFuelLevelState];
-    return (SDLComponentVolumeStatus)obj;
+- (nullable SDLComponentVolumeStatus)fuelLevel_State {
+    return [parameters sdl_objectForName:SDLNameFuelLevelState];
 }
 
-- (void)setInstantFuelConsumption:(NSNumber<SDLFloat> *)instantFuelConsumption {
+- (void)setInstantFuelConsumption:(nullable NSNumber<SDLFloat> *)instantFuelConsumption {
     [parameters sdl_setObject:instantFuelConsumption forName:SDLNameInstantFuelConsumption];
 }
 
-- (NSNumber<SDLFloat> *)instantFuelConsumption {
+- (nullable NSNumber<SDLFloat> *)instantFuelConsumption {
     return [parameters sdl_objectForName:SDLNameInstantFuelConsumption];
 }
 
-- (void)setExternalTemperature:(NSNumber<SDLFloat> *)externalTemperature {
+- (void)setExternalTemperature:(nullable NSNumber<SDLFloat> *)externalTemperature {
     [parameters sdl_setObject:externalTemperature forName:SDLNameExternalTemperature];
 }
 
-- (NSNumber<SDLFloat> *)externalTemperature {
+- (nullable NSNumber<SDLFloat> *)externalTemperature {
     return [parameters sdl_objectForName:SDLNameExternalTemperature];
 }
 
-- (void)setVin:(NSString *)vin {
+- (void)setVin:(nullable NSString *)vin {
     [parameters sdl_setObject:vin forName:SDLNameVIN];
 }
 
-- (NSString *)vin {
+- (nullable NSString *)vin {
     return [parameters sdl_objectForName:SDLNameVIN];
 }
 
-- (void)setPrndl:(SDLPRNDL)prndl {
+- (void)setPrndl:(nullable SDLPRNDL)prndl {
     [parameters sdl_setObject:prndl forName:SDLNamePRNDL];
 }
 
-- (SDLPRNDL)prndl {
+- (nullable SDLPRNDL)prndl {
     NSObject *obj = [parameters sdl_objectForName:SDLNamePRNDL];
     return (SDLPRNDL)obj;
 }
 
-- (void)setTirePressure:(SDLTireStatus *)tirePressure {
+- (void)setTirePressure:(nullable SDLTireStatus *)tirePressure {
     [parameters sdl_setObject:tirePressure forName:SDLNameTirePressure];
 }
 
-- (SDLTireStatus *)tirePressure {
-    NSObject *obj = [parameters sdl_objectForName:SDLNameTirePressure];
-    if (obj == nil || [obj isKindOfClass:SDLTireStatus.class]) {
-        return (SDLTireStatus *)obj;
-    } else {
-        return [[SDLTireStatus alloc] initWithDictionary:(NSDictionary *)obj];
-    }
+- (nullable SDLTireStatus *)tirePressure {
+    return [parameters sdl_objectForName:SDLNameTirePressure ofClass:SDLTireStatus.class];
 }
 
-- (void)setOdometer:(NSNumber<SDLInt> *)odometer {
+- (void)setOdometer:(nullable NSNumber<SDLInt> *)odometer {
     [parameters sdl_setObject:odometer forName:SDLNameOdometer];
 }
 
-- (NSNumber<SDLInt> *)odometer {
+- (nullable NSNumber<SDLInt> *)odometer {
     return [parameters sdl_objectForName:SDLNameOdometer];
 }
 
-- (void)setBeltStatus:(SDLBeltStatus *)beltStatus {
+- (void)setBeltStatus:(nullable SDLBeltStatus *)beltStatus {
     [parameters sdl_setObject:beltStatus forName:SDLNameBeltStatus];
 }
 
-- (SDLBeltStatus *)beltStatus {
-    NSObject *obj = [parameters sdl_objectForName:SDLNameBeltStatus];
-    if (obj == nil || [obj isKindOfClass:SDLBeltStatus.class]) {
-        return (SDLBeltStatus *)obj;
-    } else {
-        return [[SDLBeltStatus alloc] initWithDictionary:(NSDictionary *)obj];
-    }
+- (nullable SDLBeltStatus *)beltStatus {
+    return [parameters sdl_objectForName:SDLNameBeltStatus ofClass:SDLBeltStatus.class];
 }
 
-- (void)setBodyInformation:(SDLBodyInformation *)bodyInformation {
+- (void)setBodyInformation:(nullable SDLBodyInformation *)bodyInformation {
     [parameters sdl_setObject:bodyInformation forName:SDLNameBodyInformation];
 }
 
-- (SDLBodyInformation *)bodyInformation {
-    NSObject *obj = [parameters sdl_objectForName:SDLNameBodyInformation];
-    if (obj == nil || [obj isKindOfClass:SDLBodyInformation.class]) {
-        return (SDLBodyInformation *)obj;
-    } else {
-        return [[SDLBodyInformation alloc] initWithDictionary:(NSDictionary *)obj];
-    }
+- (nullable SDLBodyInformation *)bodyInformation {
+    return [parameters sdl_objectForName:SDLNameBodyInformation ofClass:SDLBodyInformation.class];
 }
 
-- (void)setDeviceStatus:(SDLDeviceStatus *)deviceStatus {
+- (void)setDeviceStatus:(nullable SDLDeviceStatus *)deviceStatus {
     [parameters sdl_setObject:deviceStatus forName:SDLNameDeviceStatus];
 }
 
-- (SDLDeviceStatus *)deviceStatus {
-    NSObject *obj = [parameters sdl_objectForName:SDLNameDeviceStatus];
-    if (obj == nil || [obj isKindOfClass:SDLDeviceStatus.class]) {
-        return (SDLDeviceStatus *)obj;
-    } else {
-        return [[SDLDeviceStatus alloc] initWithDictionary:(NSDictionary *)obj];
-    }
+- (nullable SDLDeviceStatus *)deviceStatus {
+    return [parameters sdl_objectForName:SDLNameDeviceStatus ofClass:SDLDeviceStatus.class];
 }
 
-- (void)setDriverBraking:(SDLVehicleDataEventStatus)driverBraking {
+- (void)setDriverBraking:(nullable SDLVehicleDataEventStatus)driverBraking {
     [parameters sdl_setObject:driverBraking forName:SDLNameDriverBraking];
 }
 
-- (SDLVehicleDataEventStatus)driverBraking {
-    NSObject *obj = [parameters sdl_objectForName:SDLNameDriverBraking];
-    return (SDLVehicleDataEventStatus)obj;
+- (nullable SDLVehicleDataEventStatus)driverBraking {
+    return [parameters sdl_objectForName:SDLNameDriverBraking];
 }
 
-- (void)setWiperStatus:(SDLWiperStatus)wiperStatus {
+- (void)setWiperStatus:(nullable SDLWiperStatus)wiperStatus {
     [parameters sdl_setObject:wiperStatus forName:SDLNameWiperStatus];
 }
 
-- (SDLWiperStatus)wiperStatus {
-    NSObject *obj = [parameters sdl_objectForName:SDLNameWiperStatus];
-    return (SDLWiperStatus)obj;
+- (nullable SDLWiperStatus)wiperStatus {
+    return [parameters sdl_objectForName:SDLNameWiperStatus];
 }
 
-- (void)setHeadLampStatus:(SDLHeadLampStatus *)headLampStatus {
+- (void)setHeadLampStatus:(nullable SDLHeadLampStatus *)headLampStatus {
     [parameters sdl_setObject:headLampStatus forName:SDLNameHeadLampStatus];
 }
 
-- (SDLHeadLampStatus *)headLampStatus {
-    NSObject *obj = [parameters sdl_objectForName:SDLNameHeadLampStatus];
-    if (obj == nil || [obj isKindOfClass:SDLHeadLampStatus.class]) {
-        return (SDLHeadLampStatus *)obj;
-    } else {
-        return [[SDLHeadLampStatus alloc] initWithDictionary:(NSDictionary *)obj];
-    }
+- (nullable SDLHeadLampStatus *)headLampStatus {
+    return [parameters sdl_objectForName:SDLNameHeadLampStatus ofClass:SDLHeadLampStatus.class];
 }
 
-- (void)setEngineTorque:(NSNumber<SDLFloat> *)engineTorque {
+- (void)setEngineTorque:(nullable NSNumber<SDLFloat> *)engineTorque {
     [parameters sdl_setObject:engineTorque forName:SDLNameEngineTorque];
 }
 
-- (NSNumber<SDLFloat> *)engineTorque {
+- (nullable NSNumber<SDLFloat> *)engineTorque {
     return [parameters sdl_objectForName:SDLNameEngineTorque];
 }
 
-- (void)setAccPedalPosition:(NSNumber<SDLFloat> *)accPedalPosition {
+- (void)setAccPedalPosition:(nullable NSNumber<SDLFloat> *)accPedalPosition {
     [parameters sdl_setObject:accPedalPosition forName:SDLNameAccelerationPedalPosition];
 }
 
-- (NSNumber<SDLFloat> *)accPedalPosition {
+- (nullable NSNumber<SDLFloat> *)accPedalPosition {
     return [parameters sdl_objectForName:SDLNameAccelerationPedalPosition];
 }
 
-- (void)setSteeringWheelAngle:(NSNumber<SDLFloat> *)steeringWheelAngle {
+- (void)setSteeringWheelAngle:(nullable NSNumber<SDLFloat> *)steeringWheelAngle {
     [parameters sdl_setObject:steeringWheelAngle forName:SDLNameSteeringWheelAngle];
 }
 
-- (NSNumber<SDLFloat> *)steeringWheelAngle {
+- (nullable NSNumber<SDLFloat> *)steeringWheelAngle {
     return [parameters sdl_objectForName:SDLNameSteeringWheelAngle];
 }
 
-- (void)setECallInfo:(SDLECallInfo *)eCallInfo {
+- (void)setECallInfo:(nullable SDLECallInfo *)eCallInfo {
     [parameters sdl_setObject:eCallInfo forName:SDLNameECallInfo];
 }
 
-- (SDLECallInfo *)eCallInfo {
-    NSObject *obj = [parameters sdl_objectForName:SDLNameECallInfo];
-    if (obj == nil || [obj isKindOfClass:SDLECallInfo.class]) {
-        return (SDLECallInfo *)obj;
-    } else {
-        return [[SDLECallInfo alloc] initWithDictionary:(NSDictionary *)obj];
-    }
+- (nullable SDLECallInfo *)eCallInfo {
+    return [parameters sdl_objectForName:SDLNameECallInfo ofClass:SDLECallInfo.class];
 }
 
-- (void)setAirbagStatus:(SDLAirbagStatus *)airbagStatus {
+- (void)setAirbagStatus:(nullable SDLAirbagStatus *)airbagStatus {
     [parameters sdl_setObject:airbagStatus forName:SDLNameAirbagStatus];
 }
 
-- (SDLAirbagStatus *)airbagStatus {
-    NSObject *obj = [parameters sdl_objectForName:SDLNameAirbagStatus];
-    if (obj == nil || [obj isKindOfClass:SDLAirbagStatus.class]) {
-        return (SDLAirbagStatus *)obj;
-    } else {
-        return [[SDLAirbagStatus alloc] initWithDictionary:(NSDictionary *)obj];
-    }
+- (nullable SDLAirbagStatus *)airbagStatus {
+    return [parameters sdl_objectForName:SDLNameAirbagStatus ofClass:SDLAirbagStatus.class];
 }
 
-- (void)setEmergencyEvent:(SDLEmergencyEvent *)emergencyEvent {
+- (void)setEmergencyEvent:(nullable SDLEmergencyEvent *)emergencyEvent {
     [parameters sdl_setObject:emergencyEvent forName:SDLNameEmergencyEvent];
 }
 
-- (SDLEmergencyEvent *)emergencyEvent {
-    NSObject *obj = [parameters sdl_objectForName:SDLNameEmergencyEvent];
-    if (obj == nil || [obj isKindOfClass:SDLEmergencyEvent.class]) {
-        return (SDLEmergencyEvent *)obj;
-    } else {
-        return [[SDLEmergencyEvent alloc] initWithDictionary:(NSDictionary *)obj];
-    }
+- (nullable SDLEmergencyEvent *)emergencyEvent {
+    return [parameters sdl_objectForName:SDLNameEmergencyEvent ofClass:SDLEmergencyEvent.class];
 }
 
-- (void)setClusterModeStatus:(SDLClusterModeStatus *)clusterModeStatus {
+- (void)setClusterModeStatus:(nullable SDLClusterModeStatus *)clusterModeStatus {
     [parameters sdl_setObject:clusterModeStatus forName:SDLNameClusterModeStatus];
 }
 
-- (SDLClusterModeStatus *)clusterModeStatus {
-    NSObject *obj = [parameters sdl_objectForName:SDLNameClusterModeStatus];
-    if (obj == nil || [obj isKindOfClass:SDLClusterModeStatus.class]) {
-        return (SDLClusterModeStatus *)obj;
-    } else {
-        return [[SDLClusterModeStatus alloc] initWithDictionary:(NSDictionary *)obj];
-    }
+- (nullable SDLClusterModeStatus *)clusterModeStatus {
+    return [parameters sdl_objectForName:SDLNameClusterModeStatus ofClass:SDLClusterModeStatus.class];
 }
 
-- (void)setMyKey:(SDLMyKey *)myKey {
+- (void)setMyKey:(nullable SDLMyKey *)myKey {
     [parameters sdl_setObject:myKey forName:SDLNameMyKey];
 }
 
-- (SDLMyKey *)myKey {
-    NSObject *obj = [parameters sdl_objectForName:SDLNameMyKey];
-    if (obj == nil || [obj isKindOfClass:SDLMyKey.class]) {
-        return (SDLMyKey *)obj;
-    } else {
-        return [[SDLMyKey alloc] initWithDictionary:(NSDictionary *)obj];
-    }
+- (nullable SDLMyKey *)myKey {
+    return [parameters sdl_objectForName:SDLNameMyKey ofClass:SDLMyKey.class];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLOnWaypointChange.h b/SmartDeviceLink/SDLOnWaypointChange.h
index 58b5fca81..7e96eae5c 100644
--- a/SmartDeviceLink/SDLOnWaypointChange.h
+++ b/SmartDeviceLink/SDLOnWaypointChange.h
@@ -5,6 +5,8 @@
 
 @class SDLLocationDetails;
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLOnWayPointChange : SDLRPCNotification
 
 /**
@@ -18,4 +20,6 @@
 
 __deprecated_msg("Use SDLOnWayPointChange instead")
     @interface SDLOnWaypointChange : SDLOnWayPointChange
-                                     @end
+@end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLOnWaypointChange.m b/SmartDeviceLink/SDLOnWaypointChange.m
index 72965ec7b..3bdeb5b86 100644
--- a/SmartDeviceLink/SDLOnWaypointChange.m
+++ b/SmartDeviceLink/SDLOnWaypointChange.m
@@ -7,6 +7,8 @@
 #import "SDLLocationDetails.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLOnWayPointChange
 
 - (instancetype)init {
@@ -28,3 +30,5 @@
 @implementation SDLOnWaypointChange
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLParameterPermissions.h b/SmartDeviceLink/SDLParameterPermissions.h
index 225028518..c2356665a 100644
--- a/SmartDeviceLink/SDLParameterPermissions.h
+++ b/SmartDeviceLink/SDLParameterPermissions.h
@@ -9,6 +9,9 @@
  *
  * @since SDL 2.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLParameterPermissions : SDLRPCStruct
 
 /**
@@ -16,12 +19,14 @@
  *
  * Required, Array of String, max String length = 100, Array size 0 - 100
  */
-@property (strong) NSMutableArray<NSString *> *allowed;
+@property (strong, nonatomic) NSMutableArray<NSString *> *allowed;
 /**
  * @abstract A set of all parameters that are prohibited for this given RPC.
  *
  * Required, Array of String, max String length = 100, Array size 0 - 100
  */
-@property (strong) NSMutableArray<NSString *> *userDisallowed;
+@property (strong, nonatomic) NSMutableArray<NSString *> *userDisallowed;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLParameterPermissions.m b/SmartDeviceLink/SDLParameterPermissions.m
index 311966bfd..9f1db88e0 100644
--- a/SmartDeviceLink/SDLParameterPermissions.m
+++ b/SmartDeviceLink/SDLParameterPermissions.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLParameterPermissions
 
 - (void)setAllowed:(NSMutableArray<NSString *> *)allowed {
@@ -26,3 +28,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLPerformAudioPassThru.h b/SmartDeviceLink/SDLPerformAudioPassThru.h
index d94f6797a..a48a44cbb 100644
--- a/SmartDeviceLink/SDLPerformAudioPassThru.h
+++ b/SmartDeviceLink/SDLPerformAudioPassThru.h
@@ -21,11 +21,14 @@
  * <p>Since SmartDeviceLink 2.0</p>
  * <p>See SDLEndAudioPassThru</p>
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLPerformAudioPassThru : SDLRPCRequest
 
 - (instancetype)initWithSamplingRate:(SDLSamplingRate)samplingRate bitsPerSample:(SDLBitsPerSample)bitsPerSample audioType:(SDLAudioType)audioType maxDuration:(UInt32)maxDuration;
 
-- (instancetype)initWithInitialPrompt:(NSString *)initialPrompt audioPassThruDisplayText1:(NSString *)audioPassThruDisplayText1 audioPassThruDisplayText2:(NSString *)audioPassThruDisplayText2 samplingRate:(SDLSamplingRate)samplingRate bitsPerSample:(SDLBitsPerSample)bitsPerSample audioType:(SDLAudioType)audioType maxDuration:(UInt32)maxDuration muteAudio:(BOOL)muteAudio;
+- (instancetype)initWithInitialPrompt:(nullable NSString *)initialPrompt audioPassThruDisplayText1:(nullable NSString *)audioPassThruDisplayText1 audioPassThruDisplayText2:(nullable NSString *)audioPassThruDisplayText2 samplingRate:(SDLSamplingRate)samplingRate bitsPerSample:(SDLBitsPerSample)bitsPerSample audioType:(SDLAudioType)audioType maxDuration:(UInt32)maxDuration muteAudio:(BOOL)muteAudio;
 
 /**
  * @abstract initial prompt which will be spoken before opening the audio pass
@@ -44,7 +47,7 @@
  *            <li>Array Maxsize: 100</li>
  *            </ul>
  */
-@property (strong) NSMutableArray<SDLTTSChunk *> *initialPrompt;
+@property (nullable, strong, nonatomic) NSMutableArray<SDLTTSChunk *> *initialPrompt;
 /**
  * @abstract a line of text displayed during audio capture
  * @discussion audioPassThruDisplayText1
@@ -53,7 +56,7 @@
  *            <p>
  *            <b>Notes: </b>Maxlength=500
  */
-@property (strong) NSString *audioPassThruDisplayText1;
+@property (nullable, strong, nonatomic) NSString *audioPassThruDisplayText1;
 /**
  * @abstract A line of text displayed during audio capture
  * @discussion audioPassThruDisplayText2
@@ -62,13 +65,13 @@
  *            <p>
  *            <b>Notes: </b>Maxlength=500
  */
-@property (strong) NSString *audioPassThruDisplayText2;
+@property (nullable, strong, nonatomic) NSString *audioPassThruDisplayText2;
 /**
  * @abstract A samplingRate
  *
  * @discussion a SamplingRate value representing a 8 or 16 or 22 or 24 khz
  */
-@property (strong) SDLSamplingRate samplingRate;
+@property (strong, nonatomic) SDLSamplingRate samplingRate;
 /**
  * @abstract the maximum duration of audio recording in milliseconds
  *
@@ -78,21 +81,23 @@
  *            <p>
  *            <b>Notes: </b>Minvalue:1; Maxvalue:1000000
  */
-@property (strong) NSNumber<SDLInt> *maxDuration;
+@property (strong, nonatomic) NSNumber<SDLInt> *maxDuration;
 /**
  * @abstract the quality the audio is recorded - 8 bit or 16 bit
  *
  * @discussion a BitsPerSample value representing 8 bit or 16 bit
  */
-@property (strong) SDLBitsPerSample bitsPerSample;
+@property (strong, nonatomic) SDLBitsPerSample bitsPerSample;
 /**
  * @abstract an audioType
  */
-@property (strong) SDLAudioType audioType;
+@property (strong, nonatomic) SDLAudioType audioType;
 /**
  * @abstract a Boolean value representing if the current audio source should be
  * muted during the APT session<br/>
  */
-@property (strong) NSNumber<SDLBool> *muteAudio;
+@property (nullable, strong, nonatomic) NSNumber<SDLBool> *muteAudio;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLPerformAudioPassThru.m b/SmartDeviceLink/SDLPerformAudioPassThru.m
index e29d45dc4..d137400f3 100644
--- a/SmartDeviceLink/SDLPerformAudioPassThru.m
+++ b/SmartDeviceLink/SDLPerformAudioPassThru.m
@@ -8,6 +8,8 @@
 #import "SDLNames.h"
 #import "SDLTTSChunk.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLPerformAudioPassThru
 
 - (instancetype)init {
@@ -16,7 +18,7 @@
     return self;
 }
 
-- (instancetype)initWithInitialPrompt:(NSString *)initialPrompt audioPassThruDisplayText1:(NSString *)audioPassThruDisplayText1 audioPassThruDisplayText2:(NSString *)audioPassThruDisplayText2 samplingRate:(SDLSamplingRate)samplingRate bitsPerSample:(SDLBitsPerSample)bitsPerSample audioType:(SDLAudioType)audioType maxDuration:(UInt32)maxDuration muteAudio:(BOOL)muteAudio {
+- (instancetype)initWithInitialPrompt:(nullable NSString *)initialPrompt audioPassThruDisplayText1:(nullable NSString *)audioPassThruDisplayText1 audioPassThruDisplayText2:(nullable NSString *)audioPassThruDisplayText2 samplingRate:(SDLSamplingRate)samplingRate bitsPerSample:(SDLBitsPerSample)bitsPerSample audioType:(SDLAudioType)audioType maxDuration:(UInt32)maxDuration muteAudio:(BOOL)muteAudio {
     self = [self initWithSamplingRate:samplingRate bitsPerSample:bitsPerSample audioType:audioType maxDuration:maxDuration];
     if (!self) {
         return nil;
@@ -44,27 +46,27 @@
     return self;
 }
 
-- (void)setInitialPrompt:(NSMutableArray<SDLTTSChunk *> *)initialPrompt {
+- (void)setInitialPrompt:(nullable NSMutableArray<SDLTTSChunk *> *)initialPrompt {
     [parameters sdl_setObject:initialPrompt forName:SDLNameInitialPrompt];
 }
 
-- (NSMutableArray<SDLTTSChunk *> *)initialPrompt {
+- (nullable NSMutableArray<SDLTTSChunk *> *)initialPrompt {
     return [parameters sdl_objectsForName:SDLNameInitialPrompt ofClass:SDLTTSChunk.class];
 }
 
-- (void)setAudioPassThruDisplayText1:(NSString *)audioPassThruDisplayText1 {
+- (void)setAudioPassThruDisplayText1:(nullable NSString *)audioPassThruDisplayText1 {
     [parameters sdl_setObject:audioPassThruDisplayText1 forName:SDLNameAudioPassThruDisplayText1];
 }
 
-- (NSString *)audioPassThruDisplayText1 {
+- (nullable NSString *)audioPassThruDisplayText1 {
     return [parameters sdl_objectForName:SDLNameAudioPassThruDisplayText1];
 }
 
-- (void)setAudioPassThruDisplayText2:(NSString *)audioPassThruDisplayText2 {
+- (void)setAudioPassThruDisplayText2:(nullable NSString *)audioPassThruDisplayText2 {
     [parameters sdl_setObject:audioPassThruDisplayText2 forName:SDLNameAudioPassThruDisplayText2];
 }
 
-- (NSString *)audioPassThruDisplayText2 {
+- (nullable NSString *)audioPassThruDisplayText2 {
     return [parameters sdl_objectForName:SDLNameAudioPassThruDisplayText2];
 }
 
@@ -101,12 +103,14 @@
     return [parameters sdl_objectForName:SDLNameAudioType];
 }
 
-- (void)setMuteAudio:(NSNumber<SDLBool> *)muteAudio {
+- (void)setMuteAudio:(nullable NSNumber<SDLBool> *)muteAudio {
     [parameters sdl_setObject:muteAudio forName:SDLNameMuteAudio];
 }
 
-- (NSNumber<SDLBool> *)muteAudio {
+- (nullable NSNumber<SDLBool> *)muteAudio {
     return [parameters sdl_objectForName:SDLNameMuteAudio];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLPerformAudioPassThruResponse.h b/SmartDeviceLink/SDLPerformAudioPassThruResponse.h
index c187f0c78..853a566bc 100644
--- a/SmartDeviceLink/SDLPerformAudioPassThruResponse.h
+++ b/SmartDeviceLink/SDLPerformAudioPassThruResponse.h
@@ -9,6 +9,11 @@
  *
  * Since SmartDeviceLink 2.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLPerformAudioPassThruResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLPerformAudioPassThruResponse.m b/SmartDeviceLink/SDLPerformAudioPassThruResponse.m
index 0ee4c124d..31a5c5a57 100644
--- a/SmartDeviceLink/SDLPerformAudioPassThruResponse.m
+++ b/SmartDeviceLink/SDLPerformAudioPassThruResponse.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLPerformAudioPassThruResponse
 
 - (instancetype)init {
@@ -16,3 +18,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLPerformInteraction.h b/SmartDeviceLink/SDLPerformInteraction.h
index 99d11886d..4c61a9fd4 100644
--- a/SmartDeviceLink/SDLPerformInteraction.h
+++ b/SmartDeviceLink/SDLPerformInteraction.h
@@ -25,23 +25,26 @@
  * Since SmartDeviceLink 1.0<br/>
  * See SDLCreateInteractionChoiceSet SDLDeleteInteractionChoiceSet
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLPerformInteraction : SDLRPCRequest
 
 - (instancetype)initWithInteractionChoiceSetId:(UInt16)interactionChoiceSetId;
 
 - (instancetype)initWithInteractionChoiceSetIdList:(NSArray<NSNumber<SDLUInt> *> *)interactionChoiceSetIdList;
 
-- (instancetype)initWithInitialPrompt:(NSString *)initialPrompt initialText:(NSString *)initialText interactionChoiceSetID:(UInt16)interactionChoiceSetID;
+- (instancetype)initWithInitialPrompt:(nullable NSString *)initialPrompt initialText:(NSString *)initialText interactionChoiceSetID:(UInt16)interactionChoiceSetID;
 
-- (instancetype)initWithInitialPrompt:(NSString *)initialPrompt initialText:(NSString *)initialText interactionChoiceSetID:(UInt16)interactionChoiceSetID vrHelp:(NSArray<SDLVRHelpItem *> *)vrHelp;
+- (instancetype)initWithInitialPrompt:(nullable NSString *)initialPrompt initialText:(NSString *)initialText interactionChoiceSetID:(UInt16)interactionChoiceSetID vrHelp:(nullable NSArray<SDLVRHelpItem *> *)vrHelp;
 
-- (instancetype)initWithInitialPrompt:(NSString *)initialPrompt initialText:(NSString *)initialText interactionChoiceSetIDList:(NSArray<NSNumber<SDLUInt> *> *)interactionChoiceSetIDList helpPrompt:(NSString *)helpPrompt timeoutPrompt:(NSString *)timeoutPrompt interactionMode:(SDLInteractionMode)interactionMode timeout:(UInt32)timeout;
+- (instancetype)initWithInitialPrompt:(nullable NSString *)initialPrompt initialText:(NSString *)initialText interactionChoiceSetIDList:(NSArray<NSNumber<SDLUInt> *> *)interactionChoiceSetIDList helpPrompt:(nullable NSString *)helpPrompt timeoutPrompt:(nullable NSString *)timeoutPrompt interactionMode:(SDLInteractionMode)interactionMode timeout:(UInt32)timeout;
 
-- (instancetype)initWithInitialPrompt:(NSString *)initialPrompt initialText:(NSString *)initialText interactionChoiceSetIDList:(NSArray<NSNumber<SDLUInt> *> *)interactionChoiceSetIDList helpPrompt:(NSString *)helpPrompt timeoutPrompt:(NSString *)timeoutPrompt interactionMode:(SDLInteractionMode)interactionMode timeout:(UInt32)timeout vrHelp:(NSArray<SDLVRHelpItem *> *)vrHelp;
+- (instancetype)initWithInitialPrompt:(nullable NSString *)initialPrompt initialText:(NSString *)initialText interactionChoiceSetIDList:(NSArray<NSNumber<SDLUInt> *> *)interactionChoiceSetIDList helpPrompt:(nullable NSString *)helpPrompt timeoutPrompt:(nullable NSString *)timeoutPrompt interactionMode:(SDLInteractionMode)interactionMode timeout:(UInt32)timeout vrHelp:(nullable NSArray<SDLVRHelpItem *> *)vrHelp;
 
-- (instancetype)initWithInitialChunks:(NSArray<SDLTTSChunk *> *)initialChunks initialText:(NSString *)initialText interactionChoiceSetIDList:(NSArray<NSNumber<SDLUInt> *> *)interactionChoiceSetIDList helpChunks:(NSArray<SDLTTSChunk *> *)helpChunks timeoutChunks:(NSArray<SDLTTSChunk *> *)timeoutChunks interactionMode:(SDLInteractionMode)interactionMode timeout:(UInt32)timeout vrHelp:(NSArray<SDLVRHelpItem *> *)vrHelp;
+- (instancetype)initWithInitialChunks:(nullable NSArray<SDLTTSChunk *> *)initialChunks initialText:(NSString *)initialText interactionChoiceSetIDList:(NSArray<NSNumber<SDLUInt> *> *)interactionChoiceSetIDList helpChunks:(nullable NSArray<SDLTTSChunk *> *)helpChunks timeoutChunks:(nullable NSArray<SDLTTSChunk *> *)timeoutChunks interactionMode:(SDLInteractionMode)interactionMode timeout:(UInt32)timeout vrHelp:(nullable NSArray<SDLVRHelpItem *> *)vrHelp;
 
-- (instancetype)initWithInitialChunks:(NSArray<SDLTTSChunk *> *)initialChunks initialText:(NSString *)initialText interactionChoiceSetIDList:(NSArray<NSNumber<SDLUInt> *> *)interactionChoiceSetIDList helpChunks:(NSArray<SDLTTSChunk *> *)helpChunks timeoutChunks:(NSArray<SDLTTSChunk *> *)timeoutChunks interactionMode:(SDLInteractionMode)interactionMode timeout:(UInt32)timeout vrHelp:(NSArray<SDLVRHelpItem *> *)vrHelp interactionLayout:(SDLLayoutMode)layout;
+- (instancetype)initWithInitialChunks:(nullable NSArray<SDLTTSChunk *> *)initialChunks initialText:(NSString *)initialText interactionChoiceSetIDList:(NSArray<NSNumber<SDLUInt> *> *)interactionChoiceSetIDList helpChunks:(nullable NSArray<SDLTTSChunk *> *)helpChunks timeoutChunks:(nullable NSArray<SDLTTSChunk *> *)timeoutChunks interactionMode:(SDLInteractionMode)interactionMode timeout:(UInt32)timeout vrHelp:(nullable NSArray<SDLVRHelpItem *> *)vrHelp interactionLayout:(nullable SDLLayoutMode)layout;
 
 /**
  * @abstract The Text that Displayed when the interaction begins. This text may
@@ -49,44 +52,46 @@
  * displayed on first line of multiline display, and is centered. If text
  * does not fit on line, it will be truncated
  */
-@property (strong) NSString *initialText;
+@property (strong, nonatomic) NSString *initialText;
 /**
  * @abstract An array of one or more TTSChunks that, taken together, specify
  * what is to be spoken to the user at the start of an interaction
  */
-@property (strong) NSMutableArray<SDLTTSChunk *> *initialPrompt;
+@property (nullable, strong, nonatomic) NSMutableArray<SDLTTSChunk *> *initialPrompt;
 /**
  * @abstract The Indicates mode that indicate how user selects interaction
  * choice. User can choose either by voice (VR_ONLY), by visual selection
  * from the menu (MANUAL_ONLY), or by either mode (BOTH)
  */
-@property (strong) SDLInteractionMode interactionMode;
+@property (strong, nonatomic) SDLInteractionMode interactionMode;
 /**
  * @abstract A Vector<Integer> value representing an Array of one or more Choice
  * Set IDs
  */
-@property (strong) NSMutableArray<NSNumber<SDLInt> *> *interactionChoiceSetIDList;
+@property (strong, nonatomic) NSMutableArray<NSNumber<SDLInt> *> *interactionChoiceSetIDList;
 /**
  * @abstract A Vector<TTSChunk> which taken together, specify the help phrase to
  * be spoken when the user says "help" during the VR session
  */
-@property (strong) NSMutableArray<SDLTTSChunk *> *helpPrompt;
+@property (nullable, strong, nonatomic) NSMutableArray<SDLTTSChunk *> *helpPrompt;
 /**
  * @abstract An array of TTSChunks which, taken together, specify the phrase to
  * be spoken when the listen times out during the VR session
  */
-@property (strong) NSMutableArray<SDLTTSChunk *> *timeoutPrompt;
+@property (nullable, strong, nonatomic) NSMutableArray<SDLTTSChunk *> *timeoutPrompt;
 /**
  * @abstract An Integer value representing the amount of time, in milliseconds,
  * SDL will wait for the user to make a choice (VR or Menu)
  */
-@property (strong) NSNumber<SDLInt> *timeout;
+@property (nullable, strong, nonatomic) NSNumber<SDLInt> *timeout;
 /**
  * @abstract A Voice recognition Help, which is a suggested VR Help Items to
  * display on-screen during Perform Interaction
  * @since SmartDeviceLink 2.0
  */
-@property (strong) NSMutableArray<SDLVRHelpItem *> *vrHelp;
-@property (strong) SDLLayoutMode interactionLayout;
+@property (nullable, strong, nonatomic) NSMutableArray<SDLVRHelpItem *> *vrHelp;
+@property (nullable, strong, nonatomic) SDLLayoutMode interactionLayout;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLPerformInteraction.m b/SmartDeviceLink/SDLPerformInteraction.m
index 890a1e4d8..708902eb1 100644
--- a/SmartDeviceLink/SDLPerformInteraction.m
+++ b/SmartDeviceLink/SDLPerformInteraction.m
@@ -9,7 +9,7 @@
 #import "SDLTTSChunk.h"
 #import "SDLVRHelpItem.h"
 
-static UInt16 const SDLDefaultTimeout = 10000;
+NS_ASSUME_NONNULL_BEGIN
 
 @implementation SDLPerformInteraction
 
@@ -23,30 +23,45 @@ static UInt16 const SDLDefaultTimeout = 10000;
     return [self initWithInteractionChoiceSetIdList:@[@(interactionChoiceSetId)]];
 }
 
-- (instancetype)initWithInitialPrompt:(NSString *)initialPrompt initialText:(NSString *)initialText interactionChoiceSetID:(UInt16)interactionChoiceSetID {
-    return [self initWithInitialPrompt:initialPrompt initialText:initialText interactionChoiceSetID:interactionChoiceSetID vrHelp:nil];
+- (instancetype)initWithInitialPrompt:(nullable NSString *)initialPrompt initialText:(NSString *)initialText interactionChoiceSetID:(UInt16)interactionChoiceSetID {
+    self = [self initWithInteractionChoiceSetId:interactionChoiceSetID];
+    if (!self) {
+        return nil;
+    }
+    
+    self.initialPrompt = [SDLTTSChunk textChunksFromString:initialPrompt];
+    self.initialText = initialText;
+    
+    return self;
 }
 
-- (instancetype)initWithInitialPrompt:(NSString *)initialPrompt initialText:(NSString *)initialText interactionChoiceSetID:(UInt16)interactionChoiceSetID vrHelp:(NSArray<SDLVRHelpItem *> *)vrHelp {
-    return [self initWithInitialPrompt:initialPrompt initialText:initialText interactionChoiceSetIDList:@[@(interactionChoiceSetID)] helpPrompt:nil timeoutPrompt:nil interactionMode:nil timeout:SDLDefaultTimeout vrHelp:vrHelp];
+- (instancetype)initWithInitialPrompt:(nullable NSString *)initialPrompt initialText:(NSString *)initialText interactionChoiceSetID:(UInt16)interactionChoiceSetID vrHelp:(nullable NSArray<SDLVRHelpItem *> *)vrHelp {
+    self = [self initWithInitialPrompt:initialPrompt initialText:initialText interactionChoiceSetID:interactionChoiceSetID];
+    if (!self) {
+        return nil;
+    }
+    
+    self.vrHelp = [vrHelp mutableCopy];
+    
+    return self;
 }
 
-- (instancetype)initWithInitialPrompt:(NSString *)initialPrompt initialText:(NSString *)initialText interactionChoiceSetIDList:(NSArray<NSNumber<SDLUInt> *> *)interactionChoiceSetIDList helpPrompt:(NSString *)helpPrompt timeoutPrompt:(NSString *)timeoutPrompt interactionMode:(SDLInteractionMode)interactionMode timeout:(UInt32)timeout {
+- (instancetype)initWithInitialPrompt:(nullable NSString *)initialPrompt initialText:(NSString *)initialText interactionChoiceSetIDList:(NSArray<NSNumber<SDLUInt> *> *)interactionChoiceSetIDList helpPrompt:(nullable NSString *)helpPrompt timeoutPrompt:(nullable NSString *)timeoutPrompt interactionMode:(SDLInteractionMode)interactionMode timeout:(UInt32)timeout {
     return [self initWithInitialPrompt:initialPrompt initialText:initialText interactionChoiceSetIDList:interactionChoiceSetIDList helpPrompt:helpPrompt timeoutPrompt:timeoutPrompt interactionMode:interactionMode timeout:timeout vrHelp:nil];
 }
 
-- (instancetype)initWithInitialPrompt:(NSString *)initialPrompt initialText:(NSString *)initialText interactionChoiceSetIDList:(NSArray<NSNumber<SDLUInt> *> *)interactionChoiceSetIDList helpPrompt:(NSString *)helpPrompt timeoutPrompt:(NSString *)timeoutPrompt interactionMode:(SDLInteractionMode)interactionMode timeout:(UInt32)timeout vrHelp:(NSArray<SDLVRHelpItem *> *)vrHelp {
+- (instancetype)initWithInitialPrompt:(nullable NSString *)initialPrompt initialText:(NSString *)initialText interactionChoiceSetIDList:(NSArray<NSNumber<SDLUInt> *> *)interactionChoiceSetIDList helpPrompt:(nullable NSString *)helpPrompt timeoutPrompt:(nullable NSString *)timeoutPrompt interactionMode:(SDLInteractionMode)interactionMode timeout:(UInt32)timeout vrHelp:(nullable NSArray<SDLVRHelpItem *> *)vrHelp {
     NSMutableArray *initialChunks = [SDLTTSChunk textChunksFromString:initialPrompt];
     NSMutableArray *helpChunks = [SDLTTSChunk textChunksFromString:helpPrompt];
     NSMutableArray *timeoutChunks = [SDLTTSChunk textChunksFromString:timeoutPrompt];
     return [self initWithInitialChunks:initialChunks initialText:initialText interactionChoiceSetIDList:interactionChoiceSetIDList helpChunks:helpChunks timeoutChunks:timeoutChunks interactionMode:interactionMode timeout:timeout vrHelp:vrHelp];
 }
 
-- (instancetype)initWithInitialChunks:(NSArray<SDLTTSChunk *> *)initialChunks initialText:(NSString *)initialText interactionChoiceSetIDList:(NSArray<NSNumber<SDLUInt> *> *)interactionChoiceSetIDList helpChunks:(NSArray *)helpChunks timeoutChunks:(NSArray<SDLTTSChunk *> *)timeoutChunks interactionMode:(SDLInteractionMode)interactionMode timeout:(UInt32)timeout vrHelp:(NSArray<SDLVRHelpItem *> *)vrHelp {
+- (instancetype)initWithInitialChunks:(nullable NSArray<SDLTTSChunk *> *)initialChunks initialText:(NSString *)initialText interactionChoiceSetIDList:(NSArray<NSNumber<SDLUInt> *> *)interactionChoiceSetIDList helpChunks:(nullable NSArray<SDLTTSChunk *> *)helpChunks timeoutChunks:(nullable NSArray<SDLTTSChunk *> *)timeoutChunks interactionMode:(SDLInteractionMode)interactionMode timeout:(UInt32)timeout vrHelp:(nullable NSArray<SDLVRHelpItem *> *)vrHelp {
     return [self initWithInitialChunks:initialChunks initialText:initialText interactionChoiceSetIDList:interactionChoiceSetIDList helpChunks:helpChunks timeoutChunks:timeoutChunks interactionMode:interactionMode timeout:timeout vrHelp:vrHelp interactionLayout:nil];
 }
 
-- (instancetype)initWithInitialChunks:(NSArray<SDLTTSChunk *> *)initialChunks initialText:(NSString *)initialText interactionChoiceSetIDList:(NSArray<NSNumber<SDLUInt> *> *)interactionChoiceSetIDList helpChunks:(NSArray<SDLTTSChunk *> *)helpChunks timeoutChunks:(NSArray<SDLTTSChunk *> *)timeoutChunks interactionMode:(SDLInteractionMode)interactionMode timeout:(UInt32)timeout vrHelp:(NSArray<SDLVRHelpItem *> *)vrHelp interactionLayout:(SDLLayoutMode)layout {
+- (instancetype)initWithInitialChunks:(nullable NSArray<SDLTTSChunk *> *)initialChunks initialText:(NSString *)initialText interactionChoiceSetIDList:(NSArray<NSNumber<SDLUInt> *> *)interactionChoiceSetIDList helpChunks:(nullable NSArray<SDLTTSChunk *> *)helpChunks timeoutChunks:(nullable NSArray<SDLTTSChunk *> *)timeoutChunks interactionMode:(SDLInteractionMode)interactionMode timeout:(UInt32)timeout vrHelp:(nullable NSArray<SDLVRHelpItem *> *)vrHelp interactionLayout:(nullable SDLLayoutMode)layout {
     self = [self initWithInteractionChoiceSetIdList:interactionChoiceSetIDList];
     if (!self) {
         return nil;
@@ -83,11 +98,11 @@ static UInt16 const SDLDefaultTimeout = 10000;
     return [parameters sdl_objectForName:SDLNameInitialText];
 }
 
-- (void)setInitialPrompt:(NSMutableArray<SDLTTSChunk *> *)initialPrompt {
+- (void)setInitialPrompt:(nullable NSMutableArray<SDLTTSChunk *> *)initialPrompt {
     [parameters sdl_setObject:initialPrompt forName:SDLNameInitialPrompt];
 }
 
-- (NSMutableArray<SDLTTSChunk *> *)initialPrompt {
+- (nullable NSMutableArray<SDLTTSChunk *> *)initialPrompt {
     return [parameters sdl_objectsForName:SDLNameInitialPrompt ofClass:SDLTTSChunk.class];
 }
 
@@ -107,44 +122,46 @@ static UInt16 const SDLDefaultTimeout = 10000;
     return [parameters sdl_objectForName:SDLNameInteractionChoiceSetIdList];
 }
 
-- (void)setHelpPrompt:(NSMutableArray<SDLTTSChunk *> *)helpPrompt {
+- (void)setHelpPrompt:(nullable NSMutableArray<SDLTTSChunk *> *)helpPrompt {
     [parameters sdl_setObject:helpPrompt forName:SDLNameHelpPrompt];
 }
 
-- (NSMutableArray<SDLTTSChunk *> *)helpPrompt {
+- (nullable NSMutableArray<SDLTTSChunk *> *)helpPrompt {
     return [parameters sdl_objectsForName:SDLNameHelpPrompt ofClass:SDLTTSChunk.class];
 }
 
-- (void)setTimeoutPrompt:(NSMutableArray<SDLTTSChunk *> *)timeoutPrompt {
+- (void)setTimeoutPrompt:(nullable NSMutableArray<SDLTTSChunk *> *)timeoutPrompt {
     [parameters sdl_setObject:timeoutPrompt forName:SDLNameTimeoutPrompt];
 }
 
-- (NSMutableArray<SDLTTSChunk *> *)timeoutPrompt {
+- (nullable NSMutableArray<SDLTTSChunk *> *)timeoutPrompt {
     return [parameters sdl_objectsForName:SDLNameTimeoutPrompt ofClass:SDLTTSChunk.class];
 }
 
-- (void)setTimeout:(NSNumber<SDLInt> *)timeout {
+- (void)setTimeout:(nullable NSNumber<SDLInt> *)timeout {
     [parameters sdl_setObject:timeout forName:SDLNameTimeout];
 }
 
-- (NSNumber<SDLInt> *)timeout {
+- (nullable NSNumber<SDLInt> *)timeout {
     return [parameters sdl_objectForName:SDLNameTimeout];
 }
 
-- (void)setVrHelp:(NSMutableArray<SDLVRHelpItem *> *)vrHelp {
+- (void)setVrHelp:(nullable NSMutableArray<SDLVRHelpItem *> *)vrHelp {
     [parameters sdl_setObject:vrHelp forName:SDLNameVRHelp];
 }
 
-- (NSMutableArray<SDLVRHelpItem *> *)vrHelp {
+- (nullable NSMutableArray<SDLVRHelpItem *> *)vrHelp {
     return [parameters sdl_objectsForName:SDLNameVRHelp ofClass:SDLVRHelpItem.class];
 }
 
-- (void)setInteractionLayout:(SDLLayoutMode)interactionLayout {
+- (void)setInteractionLayout:(nullable SDLLayoutMode)interactionLayout {
     [parameters sdl_setObject:interactionLayout forName:SDLNameInteractionLayout];
 }
 
-- (SDLLayoutMode)interactionLayout {
+- (nullable SDLLayoutMode)interactionLayout {
     return [parameters sdl_objectForName:SDLNameInteractionLayout];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLPerformInteractionResponse.h b/SmartDeviceLink/SDLPerformInteractionResponse.h
index b04bd0f7f..587b0e955 100644
--- a/SmartDeviceLink/SDLPerformInteractionResponse.h
+++ b/SmartDeviceLink/SDLPerformInteractionResponse.h
@@ -11,6 +11,9 @@
  *
  * @since SDL 1.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLPerformInteractionResponse : SDLRPCResponse
 
 /**
@@ -20,7 +23,7 @@
  *
  * Optional, Integer, 0 - 2,000,000,000
  */
-@property (strong) NSNumber<SDLInt> *choiceID;
+@property (nullable, strong, nonatomic) NSNumber<SDLInt> *choiceID;
 
 /**
  * @abstract Manually entered text selection, e.g. through keyboard
@@ -29,14 +32,16 @@
  *
  * Optional, Max length 500 chars
  */
-@property (strong) NSString *manualTextEntry;
+@property (nullable, strong, nonatomic) NSString *manualTextEntry;
 
 /**
  * @abstract A *SDLTriggerSource* object which will be shown in the HMI
  *
  * @discussion Only is valid if resultCode is SUCCESS.
  */
-@property (strong) SDLTriggerSource triggerSource;
+@property (nullable, strong, nonatomic) SDLTriggerSource triggerSource;
 
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLPerformInteractionResponse.m b/SmartDeviceLink/SDLPerformInteractionResponse.m
index 6b7752560..085c844d5 100644
--- a/SmartDeviceLink/SDLPerformInteractionResponse.m
+++ b/SmartDeviceLink/SDLPerformInteractionResponse.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLPerformInteractionResponse
 
 - (instancetype)init {
@@ -15,28 +17,30 @@
     return self;
 }
 
-- (void)setChoiceID:(NSNumber<SDLInt> *)choiceID {
+- (void)setChoiceID:(nullable NSNumber<SDLInt> *)choiceID {
     [parameters sdl_setObject:choiceID forName:SDLNameChoiceId];
 }
 
-- (NSNumber<SDLInt> *)choiceID {
+- (nullable NSNumber<SDLInt> *)choiceID {
     return [parameters sdl_objectForName:SDLNameChoiceId];
 }
 
-- (void)setManualTextEntry:(NSString *)manualTextEntry {
+- (void)setManualTextEntry:(nullable NSString *)manualTextEntry {
     [parameters sdl_setObject:manualTextEntry forName:SDLNameManualTextEntry];
 }
 
-- (NSString *)manualTextEntry {
+- (nullable NSString *)manualTextEntry {
     return [parameters sdl_objectForName:SDLNameManualTextEntry];
 }
 
-- (void)setTriggerSource:(SDLTriggerSource)triggerSource {
+- (void)setTriggerSource:(nullable SDLTriggerSource)triggerSource {
     [parameters sdl_setObject:triggerSource forName:SDLNameTriggerSource];
 }
 
-- (SDLTriggerSource)triggerSource {
+- (nullable SDLTriggerSource)triggerSource {
     return [parameters sdl_objectForName:SDLNameTriggerSource];
 }
 
 @end
+    
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLPermissionItem.h b/SmartDeviceLink/SDLPermissionItem.h
index a64c11aa2..ea7eb7154 100644
--- a/SmartDeviceLink/SDLPermissionItem.h
+++ b/SmartDeviceLink/SDLPermissionItem.h
@@ -6,11 +6,14 @@
 @class SDLHMIPermissions;
 @class SDLParameterPermissions;
 
+NS_ASSUME_NONNULL_BEGIN
 
 @interface SDLPermissionItem : SDLRPCStruct
 
-@property (strong) NSString *rpcName;
-@property (strong) SDLHMIPermissions *hmiPermissions;
-@property (strong) SDLParameterPermissions *parameterPermissions;
+@property (strong, nonatomic) NSString *rpcName;
+@property (strong, nonatomic) SDLHMIPermissions *hmiPermissions;
+@property (strong, nonatomic) SDLParameterPermissions *parameterPermissions;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLPermissionItem.m b/SmartDeviceLink/SDLPermissionItem.m
index 9d03ff1e8..01cdf127b 100644
--- a/SmartDeviceLink/SDLPermissionItem.m
+++ b/SmartDeviceLink/SDLPermissionItem.m
@@ -8,6 +8,8 @@
 #import "SDLNames.h"
 #import "SDLParameterPermissions.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLPermissionItem
 
 - (void)setRpcName:(NSString *)rpcName {
@@ -35,3 +37,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLPolicyDataParser.h b/SmartDeviceLink/SDLPolicyDataParser.h
index 4e005f9fe..cdc763b1e 100644
--- a/SmartDeviceLink/SDLPolicyDataParser.h
+++ b/SmartDeviceLink/SDLPolicyDataParser.h
@@ -4,28 +4,32 @@
 
 #import <Foundation/Foundation.h>
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLPolicyDataParser : NSObject
 
-@property (assign) Byte protocolVersion;
-@property (assign) BOOL isResponseRequired;
-@property (assign) BOOL isHighBandwidth;
-@property (assign) BOOL isSigned;
-@property (assign) BOOL isEncrypted;
-@property (assign) BOOL hasESN;
-@property (assign) Byte serviceType;
-@property (assign) Byte commandType;
-@property (assign) BOOL CPUDestination;
-@property (assign) Byte encryptionKeyIndex;
-@property (assign) UInt32 payloadSize;
-@property (strong) NSData *ESN;
-@property (assign) UInt32 moduleMessageId;
-@property (assign) UInt32 serverMessageId;
-@property (assign) Byte messageStatus;
-@property (strong) NSData *initializationVector;
-@property (strong) NSData *payload;
-@property (strong) NSData *signatureTag;
+@property (assign, nonatomic) Byte protocolVersion;
+@property (assign, nonatomic) BOOL isResponseRequired;
+@property (assign, nonatomic) BOOL isHighBandwidth;
+@property (assign, nonatomic) BOOL isSigned;
+@property (assign, nonatomic) BOOL isEncrypted;
+@property (assign, nonatomic) BOOL hasESN;
+@property (assign, nonatomic) Byte serviceType;
+@property (assign, nonatomic) Byte commandType;
+@property (assign, nonatomic) BOOL CPUDestination;
+@property (assign, nonatomic) Byte encryptionKeyIndex;
+@property (assign, nonatomic) UInt32 payloadSize;
+@property (strong, nonatomic) NSData *ESN;
+@property (assign, nonatomic) UInt32 moduleMessageId;
+@property (assign, nonatomic) UInt32 serverMessageId;
+@property (assign, nonatomic) Byte messageStatus;
+@property (strong, nonatomic) NSData *initializationVector;
+@property (strong, nonatomic) NSData *payload;
+@property (strong, nonatomic) NSData *signatureTag;
 
-- (NSData *)unwrap:(NSData *)wrappedData;
+- (nullable NSData *)unwrap:(NSData *)wrappedData;
 - (void)parsePolicyData:(NSData *)data;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLPolicyDataParser.m b/SmartDeviceLink/SDLPolicyDataParser.m
index 68cfcfa44..a724d4a79 100644
--- a/SmartDeviceLink/SDLPolicyDataParser.m
+++ b/SmartDeviceLink/SDLPolicyDataParser.m
@@ -5,9 +5,11 @@
 #import "SDLPolicyDataParser.h"
 #import "SDLDebugTool.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLPolicyDataParser
 
-- (NSData *)unwrap:(NSData *)wrappedData {
+- (nullable NSData *)unwrap:(NSData *)wrappedData {
     NSData *decodedData = nil;
 
     @try {
@@ -34,10 +36,6 @@
 }
 
 - (void)parsePolicyData:(NSData *)data {
-    if (data == nil) {
-        return;
-    }
-
     @try {
         Byte *bytes = (Byte *)data.bytes;
 
@@ -95,19 +93,22 @@
         }
 
         int payloadOffset = 5;
-        if (self.isHighBandwidth)
+        if (self.isHighBandwidth) {
             payloadOffset += 11;
-        if (self.hasESN)
+        }
+        if (self.hasESN) {
             payloadOffset += self.ESN.length;
-        if (self.isEncrypted)
+        }
+        if (self.isEncrypted) {
             payloadOffset += self.initializationVector.length;
+        }
+        
         self.payload = [NSData dataWithBytes:(bytes + payloadOffset) length:self.payloadSize];
 
         if (self.isSigned) {
             int signatureTagOffset = (int)data.length - 16;
             self.signatureTag = [NSData dataWithBytes:(bytes + signatureTagOffset) length:16];
         }
-
     }
     @catch (NSException *exception) {
         [SDLDebugTool logInfo:@"Error in PolicyDataParser::parsePolicyData()"];
@@ -138,3 +139,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLPresetBankCapabilities.h b/SmartDeviceLink/SDLPresetBankCapabilities.h
index 8c0cdda32..9242bddbd 100644
--- a/SmartDeviceLink/SDLPresetBankCapabilities.h
+++ b/SmartDeviceLink/SDLPresetBankCapabilities.h
@@ -9,6 +9,9 @@
  *
  * @since SDL 2.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLPresetBankCapabilities : SDLRPCStruct
 
 /**
@@ -16,6 +19,8 @@
  *
  * Required, Boolean
  */
-@property (strong) NSNumber<SDLBool> *onScreenPresetsAvailable;
+@property (strong, nonatomic) NSNumber<SDLBool> *onScreenPresetsAvailable;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLPresetBankCapabilities.m b/SmartDeviceLink/SDLPresetBankCapabilities.m
index cec923d03..2fe43d7a7 100644
--- a/SmartDeviceLink/SDLPresetBankCapabilities.m
+++ b/SmartDeviceLink/SDLPresetBankCapabilities.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLPresetBankCapabilities
 
 - (void)setOnScreenPresetsAvailable:(NSNumber<SDLBool> *)onScreenPresetsAvailable {
@@ -18,3 +20,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLPrioritizedObjectCollection.h b/SmartDeviceLink/SDLPrioritizedObjectCollection.h
index 8cf90c805..993f7d903 100644
--- a/SmartDeviceLink/SDLPrioritizedObjectCollection.h
+++ b/SmartDeviceLink/SDLPrioritizedObjectCollection.h
@@ -5,6 +5,8 @@
 
 #import <Foundation/Foundation.h>
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLPrioritizedObjectCollection : NSObject
 
 /**
@@ -15,13 +17,15 @@
  * @param object   The object to be added to the priority collection
  * @param priority The priority to use when determining the location of the object in the collection. A lower number is considered a higher priority
  */
-- (void)addObject:(id)object withPriority:(NSInteger)priority;
+- (void)addObject:(nullable id)object withPriority:(NSInteger)priority;
 
 /**
  * Retreive the highest priority object from the collection. This also removes the object.
  *
  * @return The highest priority object retrieved from the collection.
  */
-- (id)nextObject;
+- (nullable id)nextObject;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLPrioritizedObjectCollection.m b/SmartDeviceLink/SDLPrioritizedObjectCollection.m
index c1b5b15b7..398ca4057 100644
--- a/SmartDeviceLink/SDLPrioritizedObjectCollection.m
+++ b/SmartDeviceLink/SDLPrioritizedObjectCollection.m
@@ -6,6 +6,7 @@
 #import "SDLPrioritizedObjectCollection.h"
 #import "SDLObjectWithPriority.h"
 
+NS_ASSUME_NONNULL_BEGIN
 
 @interface SDLPrioritizedObjectCollection () {
     NSMutableArray<id> *privateArray;
@@ -23,7 +24,7 @@
     return self;
 }
 
-- (void)addObject:(id)object withPriority:(NSInteger)priority {
+- (void)addObject:(nullable id)object withPriority:(NSInteger)priority {
     if (object == nil || [[NSNull null] isEqual:object]) {
         return;
     }
@@ -49,7 +50,7 @@
     }
 }
 
-- (instancetype)nextObject {
+- (nullable instancetype)nextObject {
     if (privateArray.count == 0) {
         return nil;
     }
@@ -64,3 +65,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLProtocol.h b/SmartDeviceLink/SDLProtocol.h
index 78b1c798e..a646cef45 100644
--- a/SmartDeviceLink/SDLProtocol.h
+++ b/SmartDeviceLink/SDLProtocol.h
@@ -5,12 +5,15 @@
 @class SDLProtocolHeader;
 @class SDLProtocolRecievedMessageRouter;
 
+NS_ASSUME_NONNULL_BEGIN
+
 typedef NS_ENUM(NSUInteger, SDLProtocolError) {
     SDLProtocolErrorNoSecurityManager,
 };
 
 extern NSString *const SDLProtocolSecurityErrorDomain;
 
+
 @interface SDLProtocol : SDLAbstractProtocol <SDLProtocolListener>
 
 // Sending
@@ -29,3 +32,5 @@ extern NSString *const SDLProtocolSecurityErrorDomain;
 - (void)handleBytesFromTransport:(NSData *)receivedData;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLProtocol.m b/SmartDeviceLink/SDLProtocol.m
index a6e22d9c2..53d2ee036 100644
--- a/SmartDeviceLink/SDLProtocol.m
+++ b/SmartDeviceLink/SDLProtocol.m
@@ -28,17 +28,18 @@ NSString *const SDLProtocolSecurityErrorDomain = @"com.sdl.protocol.security";
 
 typedef NSNumber SDLServiceTypeBox;
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLProtocol () {
     UInt32 _messageID;
     dispatch_queue_t _receiveQueue;
     dispatch_queue_t _sendQueue;
     SDLPrioritizedObjectCollection *_prioritizedCollection;
-    BOOL _alreadyDestructed;
 }
 
-@property (strong) NSMutableData *receiveBuffer;
-@property (strong) SDLProtocolReceivedMessageRouter *messageRouter;
-@property (nonatomic, strong) NSMutableDictionary<SDLServiceTypeBox *, SDLProtocolHeader *> *serviceHeaders;
+@property (strong, nonatomic) NSMutableData *receiveBuffer;
+@property (nullable, strong, nonatomic) SDLProtocolReceivedMessageRouter *messageRouter;
+@property (strong, nonatomic) NSMutableDictionary<SDLServiceTypeBox *, SDLProtocolHeader *> *serviceHeaders;
 @end
 
 
@@ -62,6 +63,9 @@ typedef NSNumber SDLServiceTypeBox;
     return self;
 }
 
+- (void)dealloc {
+    [SDLDebugTool logInfo:@"SDLProtocol Dealloc" withType:SDLDebugType_Transport_iAP toOutput:SDLDebugOutput_All toGroup:self.debugConsoleGroupName];
+}
 
 #pragma mark - Service metadata
 - (UInt8)sdl_retrieveSessionIDforServiceType:(SDLServiceType)serviceType {
@@ -102,7 +106,7 @@ typedef NSNumber SDLServiceTypeBox;
 }
 
 - (SDLProtocolMessage *)sdl_createStartServiceMessageWithType:(SDLServiceType)serviceType encrypted:(BOOL)encryption {
-    SDLProtocolHeader *header = [SDLProtocolHeader headerForVersion:[SDLGlobals globals].protocolVersion];
+    SDLProtocolHeader *header = [SDLProtocolHeader headerForVersion:[SDLGlobals sharedGlobals].protocolVersion];
     switch (serviceType) {
         case SDLServiceType_RPC: {
             // Need a different header for starting the RPC service, we get the session Id from the HU, or its the same as the RPC service's
@@ -127,7 +131,7 @@ typedef NSNumber SDLServiceTypeBox;
     return [SDLProtocolMessage messageWithHeader:header andPayload:nil];
 }
 
-- (void)sdl_initializeTLSEncryptionWithCompletionHandler:(void (^)(BOOL success, NSError *error))completionHandler {
+- (void)sdl_initializeTLSEncryptionWithCompletionHandler:(void (^)(BOOL success, NSError *_Nullable error))completionHandler {
     if (self.securityManager == nil) {
         [SDLDebugTool logInfo:@"Could not start service, encryption was requested but failed because no security manager has been set."];
 
@@ -163,7 +167,7 @@ typedef NSNumber SDLServiceTypeBox;
 }
 
 - (void)endServiceWithType:(SDLServiceType)serviceType {
-    SDLProtocolHeader *header = [SDLProtocolHeader headerForVersion:[SDLGlobals globals].protocolVersion];
+    SDLProtocolHeader *header = [SDLProtocolHeader headerForVersion:[SDLGlobals sharedGlobals].protocolVersion];
     header.frameType = SDLFrameType_Control;
     header.serviceType = serviceType;
     header.frameData = SDLFrameData_EndSession;
@@ -183,7 +187,7 @@ typedef NSNumber SDLServiceTypeBox;
 - (BOOL)sendRPC:(SDLRPCMessage *)message encrypted:(BOOL)encryption error:(NSError *__autoreleasing *)error {
     NSParameterAssert(message != nil);
 
-    NSData *jsonData = [NSJSONSerialization dataWithJSONObject:[message serializeAsDictionary:[SDLGlobals globals].protocolVersion] options:kNilOptions error:error];
+    NSData *jsonData = [NSJSONSerialization dataWithJSONObject:[message serializeAsDictionary:[SDLGlobals sharedGlobals].protocolVersion] options:kNilOptions error:error];
     
     if (error != nil) {
         [SDLDebugTool logInfo:[NSString stringWithFormat:@"Error encoding JSON data: %@", *error] withType:SDLDebugType_Protocol];
@@ -196,7 +200,7 @@ typedef NSNumber SDLServiceTypeBox;
 
     // Build the message payload. Include the binary header if necessary
     // VERSION DEPENDENT CODE
-    switch ([SDLGlobals globals].protocolVersion) {
+    switch ([SDLGlobals sharedGlobals].protocolVersion) {
         case 1: {
             // No binary header in version 1
             messagePayload = jsonData;
@@ -233,12 +237,12 @@ typedef NSNumber SDLServiceTypeBox;
             }
         } break;
         default: {
-            NSAssert(NO, @"Attempting to send an RPC based on an unknown version number: %@, message: %@", @([SDLGlobals globals].protocolVersion), message);
+            NSAssert(NO, @"Attempting to send an RPC based on an unknown version number: %@, message: %@", @([SDLGlobals sharedGlobals].protocolVersion), message);
         } break;
     }
 
     // Build the protocol level header & message
-    SDLProtocolHeader *header = [SDLProtocolHeader headerForVersion:[SDLGlobals globals].protocolVersion];
+    SDLProtocolHeader *header = [SDLProtocolHeader headerForVersion:[SDLGlobals sharedGlobals].protocolVersion];
     header.encrypted = encryption;
     header.frameType = SDLFrameType_Single;
     header.serviceType = (message.bulkData.length <= 0) ? SDLServiceType_RPC : SDLServiceType_BulkData;
@@ -247,7 +251,7 @@ typedef NSNumber SDLServiceTypeBox;
     header.bytesInPayload = (UInt32)messagePayload.length;
 
     // V2+ messages need to have message ID property set.
-    if ([SDLGlobals globals].protocolVersion >= 2) {
+    if ([SDLGlobals sharedGlobals].protocolVersion >= 2) {
         [((SDLV2ProtocolHeader *)header) setMessageID:++_messageID];
     }
 
@@ -255,11 +259,11 @@ typedef NSNumber SDLServiceTypeBox;
     SDLProtocolMessage *protocolMessage = [SDLProtocolMessage messageWithHeader:header andPayload:messagePayload];
 
     // See if the message is small enough to send in one transmission. If not, break it up into smaller messages and send.
-    if (protocolMessage.size < [SDLGlobals globals].maxMTUSize) {
+    if (protocolMessage.size < [SDLGlobals sharedGlobals].maxMTUSize) {
         [self sdl_logRPCSend:protocolMessage];
         [self sdl_sendDataToTransport:protocolMessage.data onService:SDLServiceType_RPC];
     } else {
-        NSArray<SDLProtocolMessage *> *messages = [SDLProtocolMessageDisassembler disassemble:protocolMessage withLimit:[SDLGlobals globals].maxMTUSize];
+        NSArray<SDLProtocolMessage *> *messages = [SDLProtocolMessageDisassembler disassemble:protocolMessage withLimit:[SDLGlobals sharedGlobals].maxMTUSize];
         for (SDLProtocolMessage *smallerMessage in messages) {
             [self sdl_logRPCSend:smallerMessage];
             [self sdl_sendDataToTransport:smallerMessage.data onService:SDLServiceType_RPC];
@@ -301,7 +305,7 @@ typedef NSNumber SDLServiceTypeBox;
 }
 
 - (void)sdl_sendRawData:(NSData *)data onService:(SDLServiceType)service encryption:(BOOL)encryption {
-    SDLV2ProtocolHeader *header = [[SDLV2ProtocolHeader alloc] initWithVersion:[SDLGlobals globals].protocolVersion];
+    SDLV2ProtocolHeader *header = [[SDLV2ProtocolHeader alloc] initWithVersion:[SDLGlobals sharedGlobals].protocolVersion];
     header.encrypted = encryption;
     header.frameType = SDLFrameType_Single;
     header.serviceType = service;
@@ -322,11 +326,11 @@ typedef NSNumber SDLServiceTypeBox;
 
     SDLProtocolMessage *message = [SDLProtocolMessage messageWithHeader:header andPayload:data];
 
-    if (message.size < [SDLGlobals globals].maxMTUSize) {
+    if (message.size < [SDLGlobals sharedGlobals].maxMTUSize) {
         [self sdl_logRPCSend:message];
         [self sdl_sendDataToTransport:message.data onService:header.serviceType];
     } else {
-        NSArray<SDLProtocolMessage *> *messages = [SDLProtocolMessageDisassembler disassemble:message withLimit:[SDLGlobals globals].maxMTUSize];
+        NSArray<SDLProtocolMessage *> *messages = [SDLProtocolMessageDisassembler disassemble:message withLimit:[SDLGlobals sharedGlobals].maxMTUSize];
         for (SDLProtocolMessage *smallerMessage in messages) {
             [self sdl_logRPCSend:smallerMessage];
             [self sdl_sendDataToTransport:smallerMessage.data onService:header.serviceType];
@@ -341,7 +345,7 @@ typedef NSNumber SDLServiceTypeBox;
 - (void)handleBytesFromTransport:(NSData *)receivedData {
     // Initialize the receive buffer which will contain bytes while messages are constructed.
     if (self.receiveBuffer == nil) {
-        self.receiveBuffer = [NSMutableData dataWithCapacity:(4 * [SDLGlobals globals].maxMTUSize)];
+        self.receiveBuffer = [NSMutableData dataWithCapacity:(4 * [SDLGlobals sharedGlobals].maxMTUSize)];
     }
 
     // Save the data
@@ -411,7 +415,7 @@ typedef NSNumber SDLServiceTypeBox;
 - (void)handleProtocolStartSessionACK:(SDLProtocolHeader *)header {
     switch (header.serviceType) {
         case SDLServiceType_RPC: {
-            [SDLGlobals globals].maxHeadUnitVersion = header.version;
+            [SDLGlobals sharedGlobals].maxHeadUnitVersion = header.version;
         } break;
         default:
             break;
@@ -466,7 +470,7 @@ typedef NSNumber SDLServiceTypeBox;
 
 - (void)handleHeartbeatForSession:(Byte)session {
     // Respond with a heartbeat ACK
-    SDLProtocolHeader *header = [SDLProtocolHeader headerForVersion:[SDLGlobals globals].protocolVersion];
+    SDLProtocolHeader *header = [SDLProtocolHeader headerForVersion:[SDLGlobals sharedGlobals].protocolVersion];
     header.frameType = SDLFrameType_Control;
     header.serviceType = SDLServiceType_Control;
     header.frameData = SDLFrameData_HeartbeatACK;
@@ -613,26 +617,6 @@ typedef NSNumber SDLServiceTypeBox;
     return [SDLProtocolMessage messageWithHeader:serverMessageHeader andPayload:binaryData];
 }
 
-
-#pragma mark - Lifecycle
-
-- (void)sdl_destructObjects {
-    if (!_alreadyDestructed) {
-        _alreadyDestructed = YES;
-        _messageRouter.delegate = nil;
-        _messageRouter = nil;
-        self.transport = nil;
-        self.protocolDelegateTable = nil;
-    }
-}
-
-- (void)dispose {
-    [self sdl_destructObjects];
-}
-
-- (void)dealloc {
-    [self sdl_destructObjects];
-    [SDLDebugTool logInfo:@"SDLProtocol Dealloc" withType:SDLDebugType_Transport_iAP toOutput:SDLDebugOutput_All toGroup:self.debugConsoleGroupName];
-}
-
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLProtocolHeader.h b/SmartDeviceLink/SDLProtocolHeader.h
index dc8cbb788..97c405db2 100644
--- a/SmartDeviceLink/SDLProtocolHeader.h
+++ b/SmartDeviceLink/SDLProtocolHeader.h
@@ -37,26 +37,29 @@ typedef NS_ENUM(UInt8, SDLFrameData) {
     SDLFrameData_ConsecutiveLastFrame = 0x00
 };
 
+NS_ASSUME_NONNULL_BEGIN
 
 @interface SDLProtocolHeader : NSObject <NSCopying> {
     UInt8 _version;
     NSUInteger _size;
 }
 
-@property (assign, readonly) UInt8 version;
-@property (assign, readonly) NSUInteger size;
-@property (assign) BOOL compressed __deprecated_msg("This is a mirror for encrypted");
-@property (assign) BOOL encrypted;
-@property (assign) SDLFrameType frameType;
-@property (assign) SDLServiceType serviceType;
-@property (assign) SDLFrameData frameData;
-@property (assign) UInt8 sessionID;
-@property (assign) UInt32 bytesInPayload;
+@property (assign, nonatomic, readonly) UInt8 version;
+@property (assign, nonatomic, readonly) NSUInteger size;
+@property (assign, nonatomic) BOOL compressed __deprecated_msg("This is a mirror for encrypted");
+@property (assign, nonatomic) BOOL encrypted;
+@property (assign, nonatomic) SDLFrameType frameType;
+@property (assign, nonatomic) SDLServiceType serviceType;
+@property (assign, nonatomic) SDLFrameData frameData;
+@property (assign, nonatomic) UInt8 sessionID;
+@property (assign, nonatomic) UInt32 bytesInPayload;
 
 - (instancetype)init;
-- (NSData *)data;
+- (nullable NSData *)data;
 - (void)parse:(NSData *)data;
 - (NSString *)description;
 + (__kindof SDLProtocolHeader *)headerForVersion:(UInt8)version;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLProtocolHeader.m b/SmartDeviceLink/SDLProtocolHeader.m
index 65e025c61..6dbf21c38 100644
--- a/SmartDeviceLink/SDLProtocolHeader.m
+++ b/SmartDeviceLink/SDLProtocolHeader.m
@@ -6,6 +6,8 @@
 #import "SDLV1ProtocolHeader.h"
 #import "SDLV2ProtocolHeader.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLProtocolHeader
 
 @synthesize version = _version;
@@ -28,12 +30,12 @@
     _encrypted = compressed;
 }
 
-- (id)copyWithZone:(NSZone *)zone {
+- (id)copyWithZone:(nullable NSZone *)zone {
     [self doesNotRecognizeSelector:_cmd];
     return 0;
 }
 
-- (NSData *)data {
+- (nullable NSData *)data {
     [self doesNotRecognizeSelector:_cmd];
     return nil;
 }
@@ -66,3 +68,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLProtocolListener.h b/SmartDeviceLink/SDLProtocolListener.h
index 3371dfde3..20ad1eafd 100644
--- a/SmartDeviceLink/SDLProtocolListener.h
+++ b/SmartDeviceLink/SDLProtocolListener.h
@@ -5,6 +5,7 @@
 
 @class SDLProtocolMessage;
 
+NS_ASSUME_NONNULL_BEGIN
 
 @protocol SDLProtocolListener <NSObject>
 
@@ -22,3 +23,5 @@
 - (void)onError:(NSString *)info exception:(NSException *)e;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLProtocolMessage.h b/SmartDeviceLink/SDLProtocolMessage.h
index df5554c7c..c4400a8c7 100644
--- a/SmartDeviceLink/SDLProtocolMessage.h
+++ b/SmartDeviceLink/SDLProtocolMessage.h
@@ -5,19 +5,22 @@
 
 @class SDLProtocolHeader;
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLProtocolMessage : NSObject
 
-@property (strong) SDLProtocolHeader *header;
-@property (strong) NSData *payload;
-@property (strong, readonly) NSData *data;
+@property (strong, nonatomic) SDLProtocolHeader *header;
+@property (nullable, strong, nonatomic) NSData *payload;
+@property (strong, nonatomic, readonly) NSData *data;
 
-+ (id)messageWithHeader:(SDLProtocolHeader *)header andPayload:(NSData *)payload; // Returns a V1 or V2 object
++ (id)messageWithHeader:(SDLProtocolHeader *)header andPayload:(nullable NSData *)payload; // Returns a V1 or V2 object
 
 - (NSUInteger)size;
 - (NSString *)description;
-- (NSDictionary<NSString *, id> *)rpcDictionary; // Use for RPC type messages to obtain the data in a dictionary
+- (nullable NSDictionary<NSString *, id> *)rpcDictionary; // Use for RPC type messages to obtain the data in a dictionary
 
 + (UInt8)determineVersion:(NSData *)data;
 
-
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLProtocolMessage.m b/SmartDeviceLink/SDLProtocolMessage.m
index f59e792ec..a66327eac 100644
--- a/SmartDeviceLink/SDLProtocolMessage.m
+++ b/SmartDeviceLink/SDLProtocolMessage.m
@@ -12,11 +12,7 @@
 #import "SDLV1ProtocolMessage.h"
 #import "SDLV2ProtocolMessage.h"
 
-@interface SDLProtocolMessage ()
-
-@property (strong) NSMutableData *internalBuffer;
-
-@end
+NS_ASSUME_NONNULL_BEGIN
 
 @implementation SDLProtocolMessage
 
@@ -35,7 +31,7 @@
     return self;
 }
 
-- (NSDictionary<NSString *, id> *)rpcDictionary {
+- (nullable NSDictionary<NSString *, id> *)rpcDictionary {
     [self doesNotRecognizeSelector:_cmd];
     return nil;
 }
@@ -86,7 +82,7 @@
 }
 
 // Returns a V1 or V2 object
-+ (id)messageWithHeader:(SDLProtocolHeader *)header andPayload:(NSData *)payload {
++ (id)messageWithHeader:(SDLProtocolHeader *)header andPayload:(nullable NSData *)payload {
     SDLProtocolMessage *newMessage = nil;
 
     UInt8 version = header.version;
@@ -102,3 +98,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLProtocolMessageAssembler.h b/SmartDeviceLink/SDLProtocolMessageAssembler.h
index a4a448f3b..589d8032a 100644
--- a/SmartDeviceLink/SDLProtocolMessageAssembler.h
+++ b/SmartDeviceLink/SDLProtocolMessageAssembler.h
@@ -5,18 +5,20 @@
 
 @class SDLProtocolMessage;
 
+NS_ASSUME_NONNULL_BEGIN
 
-typedef void (^SDLMessageAssemblyCompletionHandler)(BOOL done, SDLProtocolMessage *assembledMessage);
+typedef void (^SDLMessageAssemblyCompletionHandler)(BOOL done,  SDLProtocolMessage * _Nullable assembledMessage);
 
 
 @interface SDLProtocolMessageAssembler : NSObject
 
-@property (assign, readonly) UInt8 sessionID;
-@property (assign) UInt32 frameCount; // number of consecutive frames required for reassembly
-@property (assign) UInt32 expectedBytes;
-@property (strong) NSMutableDictionary<NSNumber *, NSData *> *parts;
+@property (assign, nonatomic, readonly) UInt8 sessionID;
+@property (assign, nonatomic) UInt32 frameCount; // number of consecutive frames required for reassembly
+@property (assign, nonatomic) UInt32 expectedBytes;
 
 - (instancetype)initWithSessionID:(UInt8)sessionID;
 - (void)handleMessage:(SDLProtocolMessage *)message withCompletionHandler:(SDLMessageAssemblyCompletionHandler)completionHandler;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLProtocolMessageAssembler.m b/SmartDeviceLink/SDLProtocolMessageAssembler.m
index b43c94189..858efbd45 100644
--- a/SmartDeviceLink/SDLProtocolMessageAssembler.m
+++ b/SmartDeviceLink/SDLProtocolMessageAssembler.m
@@ -7,6 +7,14 @@
 #import "SDLProtocolHeader.h"
 #import "SDLProtocolMessage.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
+@interface SDLProtocolMessageAssembler ()
+
+@property (nullable, strong) NSMutableDictionary<NSNumber *, NSData *> *parts;
+
+@end
+
 @implementation SDLProtocolMessageAssembler
 
 - (instancetype)initWithSessionID:(UInt8)sessionID {
@@ -93,3 +101,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLProtocolMessageDisassembler.h b/SmartDeviceLink/SDLProtocolMessageDisassembler.h
index b4b8afa5c..644b1c1de 100644
--- a/SmartDeviceLink/SDLProtocolMessageDisassembler.h
+++ b/SmartDeviceLink/SDLProtocolMessageDisassembler.h
@@ -5,9 +5,12 @@
 
 @class SDLProtocolMessage;
 
+NS_ASSUME_NONNULL_BEGIN
 
 @interface SDLProtocolMessageDisassembler : NSObject
 
 + (NSArray<SDLProtocolMessage *> *)disassemble:(SDLProtocolMessage *)protocolMessage withLimit:(NSUInteger)mtu;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLProtocolMessageDisassembler.m b/SmartDeviceLink/SDLProtocolMessageDisassembler.m
index 7e3d0df3e..42e773855 100644
--- a/SmartDeviceLink/SDLProtocolMessageDisassembler.m
+++ b/SmartDeviceLink/SDLProtocolMessageDisassembler.m
@@ -5,6 +5,7 @@
 #import "SDLProtocolHeader.h"
 #import "SDLProtocolMessage.h"
 
+NS_ASSUME_NONNULL_BEGIN
 
 @implementation SDLProtocolMessageDisassembler
 
@@ -87,3 +88,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLProtocolReceivedMessageRouter.h b/SmartDeviceLink/SDLProtocolReceivedMessageRouter.h
index cd3e4c9c5..c153c0c41 100644
--- a/SmartDeviceLink/SDLProtocolReceivedMessageRouter.h
+++ b/SmartDeviceLink/SDLProtocolReceivedMessageRouter.h
@@ -5,11 +5,14 @@
 #import "SDLProtocolListener.h"
 @class SDLProtocolMessage;
 
+NS_ASSUME_NONNULL_BEGIN
 
 @interface SDLProtocolReceivedMessageRouter : NSObject
 
-@property (weak) id<SDLProtocolListener> delegate;
+@property (weak, nonatomic, nullable) id<SDLProtocolListener> delegate;
 
 - (void)handleReceivedMessage:(SDLProtocolMessage *)message;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLProtocolReceivedMessageRouter.m b/SmartDeviceLink/SDLProtocolReceivedMessageRouter.m
index a2993d78a..a3bc929a5 100644
--- a/SmartDeviceLink/SDLProtocolReceivedMessageRouter.m
+++ b/SmartDeviceLink/SDLProtocolReceivedMessageRouter.m
@@ -8,11 +8,11 @@
 #import "SDLProtocolMessage.h"
 #import "SDLProtocolMessageAssembler.h"
 
+NS_ASSUME_NONNULL_BEGIN
 
 @interface SDLProtocolReceivedMessageRouter ()
 
-@property (assign) BOOL alreadyDestructed;
-@property (strong) NSMutableDictionary<NSNumber *, SDLProtocolMessageAssembler *> *messageAssemblers;
+@property (strong, nonatomic) NSMutableDictionary<NSNumber *, SDLProtocolMessageAssembler *> *messageAssemblers;
 
 @end
 
@@ -21,7 +21,6 @@
 
 - (instancetype)init {
     if (self = [super init]) {
-        _alreadyDestructed = NO;
         self.messageAssemblers = [NSMutableDictionary dictionaryWithCapacity:2];
     }
     return self;
@@ -114,22 +113,6 @@
     [assembler handleMessage:message withCompletionHandler:completionHandler];
 }
 
-
-#pragma mark - Lifecycle
-
-- (void)sdl_destructObjects {
-    if (!self.alreadyDestructed) {
-        self.alreadyDestructed = YES;
-        self.delegate = nil;
-    }
-}
-
-- (void)sdl_dispose {
-    [self sdl_destructObjects];
-}
-
-- (void)dealloc {
-    [self sdl_destructObjects];
-}
-
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLProxy.h b/SmartDeviceLink/SDLProxy.h
index 67f402f62..81d1743f0 100644
--- a/SmartDeviceLink/SDLProxy.h
+++ b/SmartDeviceLink/SDLProxy.h
@@ -13,26 +13,26 @@
 #import "SDLProxyListener.h"
 #import "SDLSecurityType.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 __deprecated_msg("Use SDLManager instead")
     @interface SDLProxy : NSObject<SDLProtocolListener, NSStreamDelegate> {
     Byte _version;
     Byte _bulkSessionID;
     BOOL _isConnected;
-    BOOL _alreadyDestructed;
 }
 
-@property (strong) SDLAbstractProtocol *protocol;
-@property (strong) SDLAbstractTransport *transport;
-@property (readonly, copy) NSSet<NSObject<SDLProxyListener> *> *proxyListeners;
-@property (strong) SDLTimer *startSessionTimer;
-@property (copy) NSString *debugConsoleGroupName;
-@property (readonly, copy) NSString *proxyVersion;
-@property (nonatomic, strong, readonly) SDLStreamingMediaManager *streamingMediaManager;
+@property (nullable, strong, nonatomic) SDLAbstractProtocol *protocol;
+@property (nullable, strong, nonatomic) SDLAbstractTransport *transport;
+@property (readonly, copy, nonatomic) NSSet<NSObject<SDLProxyListener> *> *proxyListeners;
+@property (strong, nonatomic) SDLTimer *startSessionTimer;
+@property (copy, nonatomic) NSString *debugConsoleGroupName;
+@property (readonly, copy, nonatomic) NSString *proxyVersion;
+@property (nullable, nonatomic, strong, readonly) SDLStreamingMediaManager *streamingMediaManager;
 
 - (id)initWithTransport:(SDLAbstractTransport *)transport
                protocol:(SDLAbstractProtocol *)protocol
                delegate:(NSObject<SDLProxyListener> *)delegate;
-- (void)dispose;
 
 - (void)addDelegate:(NSObject<SDLProxyListener> *)delegate;
 - (void)removeDelegate:(NSObject<SDLProxyListener> *)delegate;
@@ -59,3 +59,5 @@ __deprecated_msg("Use SDLManager instead")
 - (void)putFileStream:(NSInputStream *)inputStream withRequest:(SDLPutFile *)putFileRPCRequest;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLProxy.m b/SmartDeviceLink/SDLProxy.m
index 1c78aee12..48c905a8c 100644
--- a/SmartDeviceLink/SDLProxy.m
+++ b/SmartDeviceLink/SDLProxy.m
@@ -41,6 +41,8 @@
 #import "SDLURLSession.h"
 #import "SDLVehicleType.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 typedef NSString SDLVehicleMake;
 
 typedef void (^URLSessionTaskCompletionHandler)(NSData *data, NSURLResponse *response, NSError *error);
@@ -51,15 +53,14 @@ const float startSessionTime = 10.0;
 const float notifyProxyClosedDelay = 0.1;
 const int POLICIES_CORRELATION_ID = 65535;
 
-
 @interface SDLProxy () {
     SDLLockScreenStatusManager *_lsm;
 }
 
 @property (copy, nonatomic) NSString *appId;
 @property (strong, nonatomic) NSMutableSet<NSObject<SDLProxyListener> *> *mutableProxyListeners;
-@property (nonatomic, strong, readwrite, nullable) SDLStreamingMediaManager *streamingMediaManager;
-@property (nonatomic, strong, nullable) SDLDisplayCapabilities *displayCapabilities;
+@property (nullable, nonatomic, strong, readwrite) SDLStreamingMediaManager *streamingMediaManager;
+@property (nullable, nonatomic, strong) SDLDisplayCapabilities *displayCapabilities;
 @property (nonatomic, strong) NSMutableDictionary<SDLVehicleMake *, Class> *securityManagers;
 
 @end
@@ -72,7 +73,6 @@ const int POLICIES_CORRELATION_ID = 65535;
     if (self = [super init]) {
         _debugConsoleGroupName = @"default";
         _lsm = [[SDLLockScreenStatusManager alloc] init];
-        _alreadyDestructed = NO;
 
         _mutableProxyListeners = [NSMutableSet setWithObject:theDelegate];
         _securityManagers = [NSMutableDictionary dictionary];
@@ -91,40 +91,16 @@ const int POLICIES_CORRELATION_ID = 65535;
     return self;
 }
 
-- (void)destructObjects {
-    if (!_alreadyDestructed) {
-        _alreadyDestructed = YES;
-
-        [[NSNotificationCenter defaultCenter] removeObserver:self];
-        [[EAAccessoryManager sharedAccessoryManager] unregisterForLocalNotifications];
-
-        [[SDLURLSession defaultSession] cancelAllTasks];
-
-        [self.protocol dispose];
-        [self.transport dispose];
-
-        _transport = nil;
-        _protocol = nil;
-        _mutableProxyListeners = nil;
-        _streamingMediaManager = nil;
-        _displayCapabilities = nil;
-    }
-}
-
-- (void)dispose {
-    if (self.transport != nil) {
-        [self.transport disconnect];
-    }
-
+- (void)dealloc {
     if (self.protocol.securityManager != nil) {
         [self.protocol.securityManager stop];
     }
-
-    [self destructObjects];
-}
-
-- (void)dealloc {
-    [self destructObjects];
+    
+    [[NSNotificationCenter defaultCenter] removeObserver:self];
+    [[EAAccessoryManager sharedAccessoryManager] unregisterForLocalNotifications];
+        
+    [[SDLURLSession defaultSession] cancelAllTasks];
+        
     [SDLDebugTool logInfo:@"SDLProxy Dealloc" withType:SDLDebugType_RPC toOutput:SDLDebugOutput_All toGroup:_debugConsoleGroupName];
 }
 
@@ -176,7 +152,7 @@ const int POLICIES_CORRELATION_ID = 65535;
     return SDLProxyVersion;
 }
 
-- (SDLStreamingMediaManager *)streamingMediaManager {
+- (nullable SDLStreamingMediaManager *)streamingMediaManager {
     if (_streamingMediaManager == nil) {
         if (self.displayCapabilities == nil) {
             @throw [NSException exceptionWithName:NSInvalidArgumentException reason:@"SDLStreamingMediaManager must be accessed only after a successful RegisterAppInterfaceResponse" userInfo:nil];
@@ -218,7 +194,7 @@ const int POLICIES_CORRELATION_ID = 65535;
     }
 }
 
-- (id<SDLSecurityType>)securityManagerForMake:(NSString *)make {
+- (nullable id<SDLSecurityType>)securityManagerForMake:(NSString *)make {
     if ((make != nil) && (self.securityManagers[make] != nil)) {
         Class securityManagerClass = self.securityManagers[make];
         self.protocol.appId = self.appId;
@@ -389,7 +365,7 @@ const int POLICIES_CORRELATION_ID = 65535;
         self.protocol.securityManager.appId = self.appId;
     }
 
-    if ([SDLGlobals globals].protocolVersion >= 4) {
+    if ([SDLGlobals sharedGlobals].protocolVersion >= 4) {
         [self sendMobileHMIState];
         // Send SDL updates to application state
         [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(sendMobileHMIState) name:UIApplicationDidBecomeActiveNotification object:nil];
@@ -592,7 +568,7 @@ const int POLICIES_CORRELATION_ID = 65535;
  *
  *  @return A parsed JSON dictionary, or nil if it couldn't be parsed
  */
-- (NSDictionary<NSString *, id> *)validateAndParseSystemRequest:(SDLOnSystemRequest *)request {
+- (nullable NSDictionary<NSString *, id> *)validateAndParseSystemRequest:(SDLOnSystemRequest *)request {
     NSString *urlString = request.url;
     SDLFileType fileType = request.fileType;
 
@@ -691,7 +667,7 @@ const int POLICIES_CORRELATION_ID = 65535;
     }
 }
 
-- (void)invokeMethodOnDelegates:(SEL)aSelector withObject:(id)object {
+- (void)invokeMethodOnDelegates:(SEL)aSelector withObject:(nullable id)object {
     dispatch_async(dispatch_get_main_queue(), ^{
         @autoreleasepool {
             for (id<SDLProxyListener> listener in self.proxyListeners) {
@@ -777,7 +753,7 @@ const int POLICIES_CORRELATION_ID = 65535;
             // Grab some bytes from the stream and send them in a SDLPutFile RPC Request
             NSUInteger currentStreamOffset = [[stream propertyForKey:NSStreamFileCurrentOffsetKey] unsignedIntegerValue];
 
-            NSMutableData *buffer = [NSMutableData dataWithLength:[SDLGlobals globals].maxMTUSize];
+            NSMutableData *buffer = [NSMutableData dataWithLength:[SDLGlobals sharedGlobals].maxMTUSize];
             NSUInteger nBytesRead = [(NSInputStream *)stream read:(uint8_t *)buffer.mutableBytes maxLength:buffer.length];
             if (nBytesRead > 0) {
                 NSData *data = [buffer subdataWithRange:NSMakeRange(0, nBytesRead)];
@@ -812,3 +788,5 @@ const int POLICIES_CORRELATION_ID = 65535;
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLProxyFactory.h b/SmartDeviceLink/SDLProxyFactory.h
index f4aee3089..5d2212e58 100644
--- a/SmartDeviceLink/SDLProxyFactory.h
+++ b/SmartDeviceLink/SDLProxyFactory.h
@@ -7,8 +7,10 @@
 
 @class SDLProxy;
 
+NS_ASSUME_NONNULL_BEGIN
+
 __deprecated_msg("Use SDLManager instead")
-    @interface SDLProxyFactory : NSObject {
+@interface SDLProxyFactory : NSObject {
 }
 
 + (SDLProxy *)buildSDLProxyWithListener:(NSObject<SDLProxyListener> *)listener;
@@ -17,3 +19,5 @@ __deprecated_msg("Use SDLManager instead")
                            tcpIPAddress:(NSString *)ipaddress
                                 tcpPort:(NSString *)port;
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLProxyFactory.m b/SmartDeviceLink/SDLProxyFactory.m
index b2320c641..8c187ce04 100644
--- a/SmartDeviceLink/SDLProxyFactory.m
+++ b/SmartDeviceLink/SDLProxyFactory.m
@@ -9,6 +9,7 @@
 #import "SDLProxy.h"
 #import "SDLTCPTransport.h"
 
+NS_ASSUME_NONNULL_BEGIN
 
 @implementation SDLProxyFactory
 
@@ -34,4 +35,6 @@
     return ret;
 }
 
-@end
\ No newline at end of file
+@end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLProxyListener.h b/SmartDeviceLink/SDLProxyListener.h
index 9b6f460f4..2d1f6e96f 100644
--- a/SmartDeviceLink/SDLProxyListener.h
+++ b/SmartDeviceLink/SDLProxyListener.h
@@ -68,6 +68,7 @@
 @class SDLUnsubscribeVehicleDataResponse;
 @class SDLUnsubscribeWaypointsResponse;
 
+NS_ASSUME_NONNULL_BEGIN
 
 @protocol SDLProxyListener <NSObject>
 
@@ -143,3 +144,5 @@
 - (void)onUnsubscribeWayPointsResponse:(SDLUnsubscribeWaypointsResponse *)response;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLPutFile.h b/SmartDeviceLink/SDLPutFile.h
index 63634a881..247228fbd 100644
--- a/SmartDeviceLink/SDLPutFile.h
+++ b/SmartDeviceLink/SDLPutFile.h
@@ -13,6 +13,9 @@
  * @see SDLDeleteFile
  * @see SDLListFiles
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLPutFile : SDLRPCRequest
 
 - (instancetype)initWithFileName:(NSString *)fileName fileType:(SDLFileType)fileType;
@@ -26,14 +29,14 @@
  *
  * Required, maxlength 255 characters
  */
-@property (strong) NSString *syncFileName;
+@property (strong, nonatomic) NSString *syncFileName;
 
 /**
  * A FileType value representing a selected file type
  *
  * Required
  */
-@property (strong) SDLFileType fileType;
+@property (strong, nonatomic) SDLFileType fileType;
 
 /**
  * A value to indicates if the file is meant to persist between
@@ -46,27 +49,29 @@
  *
  * Boolean, Optional, default = NO
  */
-@property (strong) NSNumber<SDLBool> *persistentFile;
+@property (nullable, strong, nonatomic) NSNumber<SDLBool> *persistentFile;
 
 /**
  * Indicates if the file is meant to be passed through core to elsewhere on the system. If set to TRUE, then the system will instead pass the data thru as it arrives to a predetermined area outside of core.
  *
  * Boolean, Optional, default = NO
  */
-@property (strong) NSNumber<SDLBool> *systemFile;
+@property (nullable, strong, nonatomic) NSNumber<SDLBool> *systemFile;
 
 /**
  * Offset in bytes for resuming partial data chunks.
  *
  * Integer, Optional, 0 - 100,000,000,000
  */
-@property (strong) NSNumber<SDLUInt> *offset;
+@property (nullable, strong, nonatomic) NSNumber<SDLUInt> *offset;
 
 /**
  * Length in bytes for resuming partial data chunks. If offset is set to 0, then length is the total length of the file to be downloaded
  *
  * Integer, Optional, 0 - 100,000,000,000
  */
-@property (strong) NSNumber<SDLUInt> *length;
+@property (nullable, strong, nonatomic) NSNumber<SDLUInt> *length;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLPutFile.m b/SmartDeviceLink/SDLPutFile.m
index f4e609581..5b289d4ce 100644
--- a/SmartDeviceLink/SDLPutFile.m
+++ b/SmartDeviceLink/SDLPutFile.m
@@ -6,6 +6,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLPutFile
 
 - (instancetype)init {
@@ -66,36 +68,38 @@
     return [parameters sdl_objectForName:SDLNameFileType];
 }
 
-- (void)setPersistentFile:(NSNumber<SDLBool> *)persistentFile {
+- (void)setPersistentFile:(nullable NSNumber<SDLBool> *)persistentFile {
     [parameters sdl_setObject:persistentFile forName:SDLNamePersistentFile];
 }
 
-- (NSNumber<SDLBool> *)persistentFile {
+- (nullable NSNumber<SDLBool> *)persistentFile {
     return [parameters sdl_objectForName:SDLNamePersistentFile];
 }
 
-- (void)setSystemFile:(NSNumber<SDLBool> *)systemFile {
+- (void)setSystemFile:(nullable NSNumber<SDLBool> *)systemFile {
     [parameters sdl_setObject:systemFile forName:SDLNameSystemFile];
 }
 
-- (NSNumber<SDLBool> *)systemFile {
+- (nullable NSNumber<SDLBool> *)systemFile {
     return [parameters sdl_objectForName:SDLNameSystemFile];
 }
 
-- (void)setOffset:(NSNumber<SDLUInt> *)offset {
+- (void)setOffset:(nullable NSNumber<SDLUInt> *)offset {
     [parameters sdl_setObject:offset forName:SDLNameOffset];
 }
 
-- (NSNumber<SDLUInt> *)offset {
+- (nullable NSNumber<SDLUInt> *)offset {
     return [parameters sdl_objectForName:SDLNameOffset];
 }
 
-- (void)setLength:(NSNumber<SDLUInt> *)length {
+- (void)setLength:(nullable NSNumber<SDLUInt> *)length {
     [parameters sdl_setObject:length forName:SDLNameLength];
 }
 
-- (NSNumber<SDLUInt> *)length {
+- (nullable NSNumber<SDLUInt> *)length {
     return [parameters sdl_objectForName:SDLNameLength];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLPutFileResponse.h b/SmartDeviceLink/SDLPutFileResponse.h
index 408ac87a8..dfa7a74a7 100644
--- a/SmartDeviceLink/SDLPutFileResponse.h
+++ b/SmartDeviceLink/SDLPutFileResponse.h
@@ -9,7 +9,12 @@
  *
  * Since SmartDeviceLink 2.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLPutFileResponse : SDLRPCResponse
 
-@property (strong) NSNumber<SDLInt> *spaceAvailable;
+@property (strong, nonatomic) NSNumber<SDLInt> *spaceAvailable;
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLPutFileResponse.m b/SmartDeviceLink/SDLPutFileResponse.m
index 167a1daac..6f4dffa7e 100644
--- a/SmartDeviceLink/SDLPutFileResponse.m
+++ b/SmartDeviceLink/SDLPutFileResponse.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLPutFileResponse
 
 - (instancetype)init {
@@ -24,3 +26,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLRPCMessage.h b/SmartDeviceLink/SDLRPCMessage.h
index f098dab51..3612d15c0 100644
--- a/SmartDeviceLink/SDLRPCMessage.h
+++ b/SmartDeviceLink/SDLRPCMessage.h
@@ -5,6 +5,8 @@
 
 #import "SDLRPCStruct.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLRPCMessage : SDLRPCStruct {
     NSMutableDictionary<NSString *, id> *function;
     NSMutableDictionary<NSString *, id> *parameters;
@@ -13,13 +15,15 @@
 
 - (instancetype)initWithName:(NSString *)name;
 - (instancetype)initWithDictionary:(NSDictionary<NSString *, id> *)dict;
-- (NSString *)getFunctionName;
-- (void)setFunctionName:(NSString *)functionName;
-- (NSObject *)getParameters:(NSString *)functionName;
-- (void)setParameters:(NSString *)functionName value:(NSObject *)value;
+- (nullable NSString *)getFunctionName;
+- (void)setFunctionName:(nullable NSString *)functionName;
+- (nullable NSObject *)getParameters:(NSString *)functionName;
+- (void)setParameters:(NSString *)functionName value:(nullable NSObject *)value;
 
-@property (strong) NSData *bulkData;
-@property (strong, readonly) NSString *name;
-@property (strong, readonly) NSString *messageType;
+@property (nullable, strong, nonatomic) NSData *bulkData;
+@property (strong, nonatomic, readonly) NSString *name;
+@property (strong, nonatomic, readonly) NSString *messageType;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLRPCMessage.m b/SmartDeviceLink/SDLRPCMessage.m
index 72900d5a8..140762dc2 100644
--- a/SmartDeviceLink/SDLRPCMessage.m
+++ b/SmartDeviceLink/SDLRPCMessage.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLRPCMessage
 
 @synthesize messageType;
@@ -27,7 +29,7 @@
     if (self = [super initWithDictionary:dict]) {
         NSEnumerator *enumerator = [store keyEnumerator];
         while (messageType = [enumerator nextObject]) {
-            if ([messageType isEqualToString:SDLNameBulkData] == FALSE) {
+            if (![messageType isEqualToString:SDLNameBulkData]) {
                 break;
             }
         }
@@ -41,27 +43,22 @@
     return self;
 }
 
-- (NSString *)getFunctionName {
+- (nullable NSString *)getFunctionName {
     return [function sdl_objectForName:SDLNameOperationName];
 }
 
-- (void)setFunctionName:(NSString *)functionName {
+- (void)setFunctionName:(nullable NSString *)functionName {
     [function sdl_setObject:functionName forName:SDLNameOperationName];
 }
 
-- (NSObject *)getParameters:(NSString *)functionName {
+- (nullable NSObject *)getParameters:(NSString *)functionName {
     return [parameters sdl_objectForName:functionName];
 }
 
-- (void)setParameters:(NSString *)functionName value:(NSObject *)value {
+- (void)setParameters:(NSString *)functionName value:(nullable NSObject *)value {
     [parameters sdl_setObject:value forName:functionName];
 }
 
-- (void)dealloc {
-    function = nil;
-    parameters = nil;
-}
-
 - (NSString *)name {
     return [self getFunctionName];
 }
@@ -73,3 +70,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLRPCNotification.h b/SmartDeviceLink/SDLRPCNotification.h
index 06f5ac52f..cb5044d6c 100644
--- a/SmartDeviceLink/SDLRPCNotification.h
+++ b/SmartDeviceLink/SDLRPCNotification.h
@@ -4,6 +4,10 @@
 
 #import "SDLRPCMessage.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLRPCNotification : SDLRPCMessage
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLRPCNotification.m b/SmartDeviceLink/SDLRPCNotification.m
index 1da74198a..f300a2148 100644
--- a/SmartDeviceLink/SDLRPCNotification.m
+++ b/SmartDeviceLink/SDLRPCNotification.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLRPCNotification
 
 - (instancetype)initWithName:(NSString *)name {
@@ -34,3 +36,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLRPCPayload.h b/SmartDeviceLink/SDLRPCPayload.h
index 1a490d956..5794cb5ea 100644
--- a/SmartDeviceLink/SDLRPCPayload.h
+++ b/SmartDeviceLink/SDLRPCPayload.h
@@ -6,16 +6,19 @@
 
 #import "SDLRPCMessageType.h"
 
+NS_ASSUME_NONNULL_BEGIN
 
 @interface SDLRPCPayload : NSObject
 
-@property (assign) SDLRPCMessageType rpcType;
-@property (assign) UInt32 functionID;
-@property (assign) UInt32 correlationID;
-@property (strong) NSData *jsonData;
-@property (strong) NSData *binaryData;
+@property (assign, nonatomic) SDLRPCMessageType rpcType;
+@property (assign, nonatomic) UInt32 functionID;
+@property (assign, nonatomic) UInt32 correlationID;
+@property (nullable, strong, nonatomic) NSData *jsonData;
+@property (nullable, strong, nonatomic) NSData *binaryData;
 
 - (NSData *)data;
-+ (id)rpcPayloadWithData:(NSData *)data;
++ (nullable id)rpcPayloadWithData:(NSData *)data;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLRPCPayload.m b/SmartDeviceLink/SDLRPCPayload.m
index 90c09175b..36bce9076 100644
--- a/SmartDeviceLink/SDLRPCPayload.m
+++ b/SmartDeviceLink/SDLRPCPayload.m
@@ -8,9 +8,11 @@
 
 const NSUInteger RPC_HEADER_SIZE = 12;
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLRPCPayload
 
-- (instancetype)initWithData:(NSData *)data {
+- (nullable instancetype)initWithData:(NSData *)data {
     unsigned long dataLength = data.length;
 
     if (data == nil || dataLength == 0) {
@@ -108,7 +110,9 @@ const NSUInteger RPC_HEADER_SIZE = 12;
     return description;
 }
 
-+ (id)rpcPayloadWithData:(NSData *)data {
++ (nullable id)rpcPayloadWithData:(NSData *)data {
     return [[SDLRPCPayload alloc] initWithData:data];
 }
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLRPCRequest.h b/SmartDeviceLink/SDLRPCRequest.h
index fe7fb639d..b99449aef 100644
--- a/SmartDeviceLink/SDLRPCRequest.h
+++ b/SmartDeviceLink/SDLRPCRequest.h
@@ -4,8 +4,12 @@
 
 #import "SDLRPCMessage.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLRPCRequest : SDLRPCMessage
 
-@property (strong) NSNumber<SDLInt> *correlationID;
+@property (strong, nonatomic) NSNumber<SDLInt> *correlationID;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLRPCRequest.m b/SmartDeviceLink/SDLRPCRequest.m
index 3cb47fba8..434c3e781 100644
--- a/SmartDeviceLink/SDLRPCRequest.m
+++ b/SmartDeviceLink/SDLRPCRequest.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLRPCRequest
 
 - (NSNumber<SDLInt> *)correlationID {
@@ -18,3 +20,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLRPCResponse.h b/SmartDeviceLink/SDLRPCResponse.h
index 92d573cdf..270217e4a 100644
--- a/SmartDeviceLink/SDLRPCResponse.h
+++ b/SmartDeviceLink/SDLRPCResponse.h
@@ -6,11 +6,15 @@
 
 #import "SDLResult.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLRPCResponse : SDLRPCMessage
 
-@property (strong) NSNumber<SDLInt> *correlationID;
-@property (strong) NSNumber<SDLBool> *success;
-@property (strong) SDLResult resultCode;
-@property (strong) NSString *info;
+@property (strong, nonatomic) NSNumber<SDLInt> *correlationID;
+@property (strong, nonatomic) NSNumber<SDLBool> *success;
+@property (strong, nonatomic) SDLResult resultCode;
+@property (nullable, strong, nonatomic) NSString *info;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLRPCResponse.m b/SmartDeviceLink/SDLRPCResponse.m
index 99bc961b0..f27369270 100644
--- a/SmartDeviceLink/SDLRPCResponse.m
+++ b/SmartDeviceLink/SDLRPCResponse.m
@@ -8,6 +8,8 @@
 #import "SDLNames.h"
 #import "SDLResult.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLRPCResponse
 
 - (instancetype)initWithName:(NSString *)name {
@@ -58,12 +60,14 @@
     return [store sdl_objectForName:SDLNameResultCode];
 }
 
-- (void)setInfo:(NSString *)info {
+- (void)setInfo:(nullable NSString *)info {
     [store sdl_setObject:info forName:SDLNameInfo];
 }
 
-- (NSString *)info {
+- (nullable NSString *)info {
     return [store sdl_objectForName:SDLNameInfo];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLRPCStruct.h b/SmartDeviceLink/SDLRPCStruct.h
index f69b11dcb..3a6243d21 100644
--- a/SmartDeviceLink/SDLRPCStruct.h
+++ b/SmartDeviceLink/SDLRPCStruct.h
@@ -6,6 +6,8 @@
 
 #import "NSNumber+NumberType.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLRPCStruct : NSObject {
     NSMutableDictionary<NSString *, id> *store;
 }
@@ -16,3 +18,5 @@
 - (NSDictionary<NSString *, id> *)serializeAsDictionary:(Byte)version;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLRPCStruct.m b/SmartDeviceLink/SDLRPCStruct.m
index d0be4bffb..4c8b81c29 100644
--- a/SmartDeviceLink/SDLRPCStruct.m
+++ b/SmartDeviceLink/SDLRPCStruct.m
@@ -7,6 +7,8 @@
 #import "SDLEnum.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLRPCStruct
 
 - (id)initWithDictionary:(NSDictionary<NSString *, id> *)dict {
@@ -74,3 +76,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLReadDID.h b/SmartDeviceLink/SDLReadDID.h
index 057edd488..d275f694e 100644
--- a/SmartDeviceLink/SDLReadDID.h
+++ b/SmartDeviceLink/SDLReadDID.h
@@ -16,6 +16,9 @@
  *
  * Since SmartDeviceLink 2.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLReadDID : SDLRPCRequest
 
 - (instancetype)initWithECUName:(UInt16)ecuNumber didLocation:(NSArray<NSNumber<SDLUInt> *> *)didLocation;
@@ -24,7 +27,7 @@
  * @abstract An ID of the vehicle module
  *            <br/><b>Notes: </b>Minvalue:0; Maxvalue:65535
  */
-@property (strong) NSNumber<SDLInt> *ecuName;
+@property (strong, nonatomic) NSNumber<SDLInt> *ecuName;
 
 /**
  * @abstract Raw data from vehicle data DID location(s)
@@ -37,6 +40,8 @@
  *            <li>ArrayMin:0; ArrayMax:1000</li>
  *            </ul>
  */
-@property (strong) NSMutableArray<NSNumber<SDLInt> *> *didLocation;
+@property (strong, nonatomic) NSMutableArray<NSNumber<SDLInt> *> *didLocation;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLReadDID.m b/SmartDeviceLink/SDLReadDID.m
index 2e66bdf40..5c491825e 100644
--- a/SmartDeviceLink/SDLReadDID.m
+++ b/SmartDeviceLink/SDLReadDID.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLReadDID
 
 - (instancetype)init {
@@ -44,3 +46,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLReadDIDResponse.h b/SmartDeviceLink/SDLReadDIDResponse.h
index 0c9668bf9..7fcd0ed9c 100644
--- a/SmartDeviceLink/SDLReadDIDResponse.h
+++ b/SmartDeviceLink/SDLReadDIDResponse.h
@@ -11,8 +11,13 @@
  *
  * Since SmartDeviceLink 2.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLReadDIDResponse : SDLRPCResponse
 
-@property (strong) NSMutableArray<SDLDIDResult *> *didResult;
+@property (nullable, strong, nonatomic) NSMutableArray<SDLDIDResult *> *didResult;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLReadDIDResponse.m b/SmartDeviceLink/SDLReadDIDResponse.m
index 421aa8372..a0f71b20e 100644
--- a/SmartDeviceLink/SDLReadDIDResponse.m
+++ b/SmartDeviceLink/SDLReadDIDResponse.m
@@ -8,6 +8,8 @@
 #import "SDLDIDResult.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLReadDIDResponse
 
 - (instancetype)init {
@@ -16,12 +18,14 @@
     return self;
 }
 
-- (void)setDidResult:(NSMutableArray<SDLDIDResult *> *)didResult {
+- (void)setDidResult:(nullable NSMutableArray<SDLDIDResult *> *)didResult {
     [parameters sdl_setObject:didResult forName:SDLNameDIDResult];
 }
 
-- (NSMutableArray<SDLDIDResult *> *)didResult {
+- (nullable NSMutableArray<SDLDIDResult *> *)didResult {
     return [parameters sdl_objectsForName:SDLNameDIDResult ofClass:SDLDIDResult.class];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLRegisterAppInterface.h b/SmartDeviceLink/SDLRegisterAppInterface.h
index a670e0746..a8b6fdc37 100644
--- a/SmartDeviceLink/SDLRegisterAppInterface.h
+++ b/SmartDeviceLink/SDLRegisterAppInterface.h
@@ -83,22 +83,25 @@
  *
  * @see SDLUnregisterAppInterface SDLOnAppInterfaceUnregistered
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLRegisterAppInterface : SDLRPCRequest
 
 - (instancetype)initWithLifecycleConfiguration:(SDLLifecycleConfiguration *)lifecycleConfiguration;
 
 - (instancetype)initWithAppName:(NSString *)appName appId:(NSString *)appId languageDesired:(SDLLanguage)languageDesired;
 
-- (instancetype)initWithAppName:(NSString *)appName appId:(NSString *)appId languageDesired:(SDLLanguage)languageDesired isMediaApp:(BOOL)isMediaApp appType:(SDLAppHMIType)appType shortAppName:(NSString *)shortAppName;
+- (instancetype)initWithAppName:(NSString *)appName appId:(NSString *)appId languageDesired:(SDLLanguage)languageDesired isMediaApp:(BOOL)isMediaApp appType:(SDLAppHMIType)appType shortAppName:(nullable NSString *)shortAppName;
 
-- (instancetype)initWithAppName:(NSString *)appName appId:(NSString *)appId languageDesired:(SDLLanguage)languageDesired isMediaApp:(BOOL)isMediaApp appType:(SDLAppHMIType)appType shortAppName:(NSString *)shortAppName ttsName:(NSArray<SDLTTSChunk *> *)ttsName vrSynonyms:(NSArray<NSString *> *)vrSynonyms hmiDisplayLanguageDesired:(SDLLanguage)hmiDisplayLanguageDesired resumeHash:(NSString *)resumeHash;
+- (instancetype)initWithAppName:(NSString *)appName appId:(NSString *)appId languageDesired:(SDLLanguage)languageDesired isMediaApp:(BOOL)isMediaApp appType:(SDLAppHMIType)appType shortAppName:(nullable NSString *)shortAppName ttsName:(nullable NSArray<SDLTTSChunk *> *)ttsName vrSynonyms:(nullable NSArray<NSString *> *)vrSynonyms hmiDisplayLanguageDesired:(SDLLanguage)hmiDisplayLanguageDesired resumeHash:(nullable NSString *)resumeHash;
 
 /**
  * @abstract The version of the SDL interface
  *
  * Required
  */
-@property (strong) SDLSyncMsgVersion *syncMsgVersion;
+@property (strong, nonatomic) SDLSyncMsgVersion *syncMsgVersion;
 
 /**
  * @abstract The Mobile Application's Name, This name is displayed in the SDL Mobile Applications menu. It also serves as the unique identifier of the application for SmartDeviceLink
@@ -112,7 +115,7 @@
  *
  * Required, Max length 100 chars
  */
-@property (strong) NSString *appName;
+@property (strong, nonatomic) NSString *appName;
 
 /**
  * @abstract TTS string for VR recognition of the mobile application name.
@@ -127,7 +130,7 @@
  * @since SDL 2.0
  * @see SDLTTSChunk
  */
-@property (strong) NSMutableArray<SDLTTSChunk *> *ttsName;
+@property (nullable, strong, nonatomic) NSMutableArray<SDLTTSChunk *> *ttsName;
 
 /**
  * @abstract A String representing an abbreviated version of the mobile application's name (if necessary) that will be displayed on the media screen
@@ -136,7 +139,7 @@
  *
  * Optional, Max length 100 chars
  */
-@property (strong) NSString *ngnMediaScreenAppName;
+@property (nullable, strong, nonatomic) NSString *ngnMediaScreenAppName;
 
 /**
  * @abstract Defines a additional voice recognition commands
@@ -145,7 +148,7 @@
  *
  * Optional, Array of Strings, Array length 1 - 100, Max String length 40
  */
-@property (strong) NSMutableArray<NSString *> *vrSynonyms;
+@property (nullable, strong, nonatomic) NSMutableArray<NSString *> *vrSynonyms;
 
 /**
  * @abstract Indicates if the application is a media or a non-media application.
@@ -154,7 +157,7 @@
  *
  * Required, Boolean
  */
-@property (strong) NSNumber<SDLBool> *isMediaApplication;
+@property (strong, nonatomic) NSNumber<SDLBool> *isMediaApplication;
 
 /**
  * @abstract A Language enumeration indicating what language the application intends to use for user interaction (TTS and VR).
@@ -163,7 +166,7 @@
  *
  * Required
  */
-@property (strong) SDLLanguage languageDesired;
+@property (strong, nonatomic) SDLLanguage languageDesired;
 
 /**
  * @abstract An enumeration indicating what language the application intends to use for user interaction (Display).
@@ -174,7 +177,7 @@
  *
  * @since SDL 2.0
  */
-@property (strong) SDLLanguage hmiDisplayLanguageDesired;
+@property (strong, nonatomic) SDLLanguage hmiDisplayLanguageDesired;
 
 /**
  * @abstract A list of all applicable app types stating which classifications to be given to the app.
@@ -184,7 +187,7 @@
  * @since SDL 2.0
  * @see SDLAppHMIType
  */
-@property (strong) NSMutableArray<SDLAppHMIType> *appHMIType;
+@property (nullable, strong, nonatomic) NSMutableArray<SDLAppHMIType> *appHMIType;
 
 /**
  * @abstract ID used to uniquely identify current state of all app data that can persist through connection cycles (e.g. ignition cycles).
@@ -195,14 +198,14 @@
  *
  * Optional, max length 100 chars
  */
-@property (strong) NSString *hashID;
+@property (nullable, strong, nonatomic) NSString *hashID;
 
 /**
  * @abstract Information about the connecting device
  *
  * Optional
  */
-@property (strong) SDLDeviceInfo *deviceInfo;
+@property (nullable, strong, nonatomic) SDLDeviceInfo *deviceInfo;
 
 /**
  * @abstract ID used to validate app with policy table entries
@@ -211,13 +214,15 @@
  *
  * @since SDL 2.0
  */
-@property (strong) NSString *appID;
+@property (strong, nonatomic) NSString *appID;
 
 /**
  * @abstract Information about the application running
  *
  * Optional
  */
-@property (strong) SDLAppInfo *appInfo;
+@property (nullable, strong, nonatomic) SDLAppInfo *appInfo;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLRegisterAppInterface.m b/SmartDeviceLink/SDLRegisterAppInterface.m
index 51ed34cf8..acf94b418 100644
--- a/SmartDeviceLink/SDLRegisterAppInterface.m
+++ b/SmartDeviceLink/SDLRegisterAppInterface.m
@@ -14,6 +14,7 @@
 #import "SDLSyncMsgVersion.h"
 #import "SDLTTSChunk.h"
 
+NS_ASSUME_NONNULL_BEGIN
 
 @implementation SDLRegisterAppInterface
 
@@ -28,37 +29,51 @@
 }
 
 - (instancetype)initWithAppName:(NSString *)appName appId:(NSString *)appId languageDesired:(SDLLanguage)languageDesired {
-    return [self initWithAppName:appName appId:appId languageDesired:languageDesired isMediaApp:NO appType:nil shortAppName:nil];
-}
-
-- (instancetype)initWithAppName:(NSString *)appName appId:(NSString *)appId languageDesired:(SDLLanguage)languageDesired isMediaApp:(BOOL)isMediaApp appType:(SDLAppHMIType)appType shortAppName:(NSString *)shortAppName {
-    return [self initWithAppName:appName appId:appId languageDesired:languageDesired isMediaApp:isMediaApp appType:appType shortAppName:shortAppName ttsName:nil vrSynonyms:nil hmiDisplayLanguageDesired:languageDesired resumeHash:nil];
-}
-
-- (instancetype)initWithAppName:(NSString *)appName appId:(NSString *)appId languageDesired:(SDLLanguage)languageDesired isMediaApp:(BOOL)isMediaApp appType:(SDLAppHMIType)appType shortAppName:(NSString *)shortAppName ttsName:(NSArray<SDLTTSChunk *> *)ttsName vrSynonyms:(NSArray<NSString *> *)vrSynonyms hmiDisplayLanguageDesired:(SDLLanguage)hmiDisplayLanguageDesired resumeHash:(NSString *)resumeHash {
     self = [self init];
     if (!self) {
         return nil;
     }
-
-    self.appID = appId;
+    
     self.appName = appName;
-    self.ngnMediaScreenAppName = shortAppName;
+    self.appID = appId;
+    self.languageDesired = languageDesired;
+    
+    self.syncMsgVersion = [[SDLSyncMsgVersion alloc] initWithMajorVersion:1 minorVersion:0];
+    self.appInfo = [SDLAppInfo currentAppInfo];
+    self.deviceInfo = [SDLDeviceInfo currentDevice];
+    self.correlationID = @1;
+    
+    return self;
+    
+}
+
+- (instancetype)initWithAppName:(NSString *)appName appId:(NSString *)appId languageDesired:(SDLLanguage)languageDesired isMediaApp:(BOOL)isMediaApp appType:(SDLAppHMIType)appType shortAppName:(nullable NSString *)shortAppName {
+    self = [self initWithAppName:appName appId:appId languageDesired:languageDesired];
+    if (!self) {
+        return nil;
+    }
+    
+    self.isMediaApplication = @(isMediaApp);
 
     if (appType != nil) {
         self.appHMIType = [NSMutableArray arrayWithObject:appType];
     }
+    
+    self.ngnMediaScreenAppName = shortAppName;
+    
+    return self;
+}
+
+- (instancetype)initWithAppName:(NSString *)appName appId:(NSString *)appId languageDesired:(SDLLanguage)languageDesired isMediaApp:(BOOL)isMediaApp appType:(SDLAppHMIType)appType shortAppName:(nullable NSString *)shortAppName ttsName:(nullable NSArray<SDLTTSChunk *> *)ttsName vrSynonyms:(nullable NSArray<NSString *> *)vrSynonyms hmiDisplayLanguageDesired:(SDLLanguage)hmiDisplayLanguageDesired resumeHash:(nullable NSString *)resumeHash {
+    self = [self initWithAppName:appName appId:appId languageDesired:languageDesired isMediaApp:isMediaApp appType:appType shortAppName:shortAppName];
+    if (!self) {
+        return nil;
+    }
 
-    self.languageDesired = languageDesired;
-    self.hmiDisplayLanguageDesired = hmiDisplayLanguageDesired;
-    self.isMediaApplication = @(isMediaApp);
     self.ttsName = [ttsName copy];
     self.vrSynonyms = [vrSynonyms copy];
-    self.syncMsgVersion = [[SDLSyncMsgVersion alloc] initWithMajorVersion:1 minorVersion:0];
-    self.appInfo = [SDLAppInfo currentAppInfo];
-    self.deviceInfo = [SDLDeviceInfo currentDevice];
+    self.hmiDisplayLanguageDesired = hmiDisplayLanguageDesired;
     self.hashID = resumeHash;
-    self.correlationID = @1;
 
     return self;
 }
@@ -79,27 +94,27 @@
     return [parameters sdl_objectForName:SDLNameAppName];
 }
 
-- (void)setTtsName:(NSMutableArray<SDLTTSChunk *> *)ttsName {
+- (void)setTtsName:(nullable NSMutableArray<SDLTTSChunk *> *)ttsName {
     [parameters sdl_setObject:ttsName forName:SDLNameTTSName];
 }
 
-- (NSMutableArray<SDLTTSChunk *> *)ttsName {
+- (nullable NSMutableArray<SDLTTSChunk *> *)ttsName {
     return [parameters sdl_objectsForName:SDLNameTTSName ofClass:SDLTTSChunk.class];
 }
 
-- (void)setNgnMediaScreenAppName:(NSString *)ngnMediaScreenAppName {
+- (void)setNgnMediaScreenAppName:(nullable NSString *)ngnMediaScreenAppName {
     [parameters sdl_setObject:ngnMediaScreenAppName forName:SDLNameNGNMediaScreenAppName];
 }
 
-- (NSString *)ngnMediaScreenAppName {
+- (nullable NSString *)ngnMediaScreenAppName {
     return [parameters sdl_objectForName:SDLNameNGNMediaScreenAppName];
 }
 
-- (void)setVrSynonyms:(NSMutableArray<NSString *> *)vrSynonyms {
+- (void)setVrSynonyms:(nullable NSMutableArray<NSString *> *)vrSynonyms {
     [parameters sdl_setObject:vrSynonyms forName:SDLNameVRSynonyms];
 }
 
-- (NSMutableArray<NSString *> *)vrSynonyms {
+- (nullable NSMutableArray<NSString *> *)vrSynonyms {
     return [parameters sdl_objectForName:SDLNameVRSynonyms];
 }
 
@@ -127,27 +142,27 @@
     return [parameters sdl_objectForName:SDLNameHMIDisplayLanguageDesired];
 }
 
-- (void)setAppHMIType:(NSMutableArray<SDLAppHMIType> *)appHMIType {
+- (void)setAppHMIType:(nullable NSMutableArray<SDLAppHMIType> *)appHMIType {
     [parameters sdl_setObject:appHMIType forName:SDLNameAppHMIType];
 }
 
-- (NSMutableArray<SDLAppHMIType> *)appHMIType {
+- (nullable NSMutableArray<SDLAppHMIType> *)appHMIType {
     return [parameters sdl_enumsForName:SDLNameAppHMIType];
 }
 
-- (void)setHashID:(NSString *)hashID {
+- (void)setHashID:(nullable NSString *)hashID {
     [parameters sdl_setObject:hashID forName:SDLNameHashId];
 }
 
-- (NSString *)hashID {
+- (nullable NSString *)hashID {
     return [parameters sdl_objectForName:SDLNameHashId];
 }
 
-- (void)setDeviceInfo:(SDLDeviceInfo *)deviceInfo {
+- (void)setDeviceInfo:(nullable SDLDeviceInfo *)deviceInfo {
     [parameters sdl_setObject:deviceInfo forName:SDLNameDeviceInfo];
 }
 
-- (SDLDeviceInfo *)deviceInfo {
+- (nullable SDLDeviceInfo *)deviceInfo {
     return [parameters sdl_objectForName:SDLNameDeviceInfo ofClass:SDLDeviceInfo.class];
 }
 
@@ -159,12 +174,14 @@
     return [parameters sdl_objectForName:SDLNameAppId];
 }
 
-- (void)setAppInfo:(SDLAppInfo *)appInfo {
+- (void)setAppInfo:(nullable SDLAppInfo *)appInfo {
     [parameters sdl_setObject:appInfo forName:SDLNameAppInfo];
 }
 
-- (SDLAppInfo *)appInfo {
+- (nullable SDLAppInfo *)appInfo {
     return [parameters sdl_objectForName:SDLNameAppInfo ofClass:SDLAppInfo.class];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLRegisterAppInterfaceResponse.h b/SmartDeviceLink/SDLRegisterAppInterfaceResponse.h
index aac85c457..32dc5e40c 100644
--- a/SmartDeviceLink/SDLRegisterAppInterfaceResponse.h
+++ b/SmartDeviceLink/SDLRegisterAppInterfaceResponse.h
@@ -25,6 +25,9 @@
  *
  * Since SmartDeviceLink 1.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLRegisterAppInterfaceResponse : SDLRPCResponse
 
 /**
@@ -32,7 +35,7 @@
  *
  * Optional
  */
-@property (strong) SDLSyncMsgVersion *syncMsgVersion;
+@property (nullable, strong, nonatomic) SDLSyncMsgVersion *syncMsgVersion;
 
 /**
  * The currently active VR+TTS language on Sync.
@@ -41,7 +44,7 @@
  *
  * Optional
  */
-@property (strong) SDLLanguage language;
+@property (nullable, strong, nonatomic) SDLLanguage language;
 
 /**
  * The currently active display language on Sync
@@ -51,21 +54,21 @@
  *
  * Optional
  */
-@property (strong) SDLLanguage hmiDisplayLanguage;
+@property (nullable, strong, nonatomic) SDLLanguage hmiDisplayLanguage;
 
 /**
  * @see SDLDisplayCapabilities
  *
  * Optional
  */
-@property (strong) SDLDisplayCapabilities *displayCapabilities;
+@property (nullable, strong, nonatomic) SDLDisplayCapabilities *displayCapabilities;
 
 /**
  * @see SDLButtonCapabilities
  *
  * Optional, Array of length 1 - 100, of SDLButtonCapabilities
  */
-@property (strong) NSMutableArray<SDLButtonCapabilities *> *buttonCapabilities;
+@property (nullable, strong, nonatomic) NSMutableArray<SDLButtonCapabilities *> *buttonCapabilities;
 
 /**
  * If returned, the platform supports on-screen SoftButtons
@@ -74,7 +77,7 @@
  *
  * Optional, Array of length 1 - 100, of SDLSoftButtonCapabilities
  */
-@property (strong) NSMutableArray<SDLSoftButtonCapabilities *> *softButtonCapabilities;
+@property (nullable, strong, nonatomic) NSMutableArray<SDLSoftButtonCapabilities *> *softButtonCapabilities;
 
 /**
  * If returned, the platform supports custom on-screen Presets
@@ -83,42 +86,42 @@
  *
  * Optional
  */
-@property (strong) SDLPresetBankCapabilities *presetBankCapabilities;
+@property (nullable, strong, nonatomic) SDLPresetBankCapabilities *presetBankCapabilities;
 
 /**
  * @see SDLHMIZoneCapabilities
  *
  * Optional, Array of length 1 - 100, of SDLHMIZoneCapabilities
  */
-@property (strong) NSMutableArray<SDLHMIZoneCapabilities> *hmiZoneCapabilities;
+@property (nullable, strong, nonatomic) NSMutableArray<SDLHMIZoneCapabilities> *hmiZoneCapabilities;
 
 /**
  * @see SDLSpeechCapabilities
  *
  * Optional, Array of length 1 - 100, of SDLSpeechCapabilities
  */
-@property (strong) NSMutableArray<SDLSpeechCapabilities> *speechCapabilities;
+@property (nullable, strong, nonatomic) NSMutableArray<SDLSpeechCapabilities> *speechCapabilities;
 
 /**
  * @see SDLPrerecordedSpeech
  *
  * Optional, Array of length 1 - 100, of SDLPrerecordedSpeech
  */
-@property (strong) NSMutableArray<SDLPrerecordedSpeech> *prerecordedSpeech;
+@property (nullable, strong, nonatomic) NSMutableArray<SDLPrerecordedSpeech> *prerecordedSpeech;
 
 /**
  * @see SDLVRCapabilities
  *
  * Optional, Array of length 1 - 100, of SDLVRCapabilities
  */
-@property (strong) NSMutableArray<SDLVRCapabilities> *vrCapabilities;
+@property (nullable, strong, nonatomic) NSMutableArray<SDLVRCapabilities> *vrCapabilities;
 
 /**
  * @see SDLAudioPassThruCapabilities
  *
  * Optional, Array of length 1 - 100, of SDLAudioPassThruCapabilities
  */
-@property (strong) NSMutableArray<SDLAudioPassThruCapabilities *> *audioPassThruCapabilities;
+@property (nullable, strong, nonatomic) NSMutableArray<SDLAudioPassThruCapabilities *> *audioPassThruCapabilities;
 
 /**
  * Specifies the vehicle's type
@@ -127,35 +130,37 @@
  *
  * Optional, Array of length 1 - 100, of SDLVehicleType
  */
-@property (strong) SDLVehicleType *vehicleType;
+@property (nullable, strong, nonatomic) SDLVehicleType *vehicleType;
 
 /**
  * Specifies the white-list of supported diagnostic modes (0x00-0xFF) capable for DiagnosticMessage requests. If a mode outside this list is requested, it will be rejected.
  *
  * Optional, Array of length 1 - 100, Integer 0 - 255
  */
-@property (strong) NSMutableArray<NSNumber<SDLInt> *> *supportedDiagModes;
+@property (nullable, strong, nonatomic) NSMutableArray<NSNumber<SDLInt> *> *supportedDiagModes;
 
 /**
  * @see SDLHMICapabilities
  *
  * Optional
  */
-@property (strong) SDLHMICapabilities *hmiCapabilities;
+@property (nullable, strong, nonatomic) SDLHMICapabilities *hmiCapabilities;
 
 /**
  * The SmartDeviceLink version
  *
  * Optional, String max length 100
  */
-@property (strong) NSString *sdlVersion;
+@property (nullable, strong, nonatomic) NSString *sdlVersion;
 
 /**
  * The software version of the system that implements the SmartDeviceLink core
  *
  * Optional, String max length 100
  */
-@property (strong) NSString *systemSoftwareVersion;
+@property (nullable, strong, nonatomic) NSString *systemSoftwareVersion;
 
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLRegisterAppInterfaceResponse.m b/SmartDeviceLink/SDLRegisterAppInterfaceResponse.m
index 95f0fee34..e26c64431 100644
--- a/SmartDeviceLink/SDLRegisterAppInterfaceResponse.m
+++ b/SmartDeviceLink/SDLRegisterAppInterfaceResponse.m
@@ -15,6 +15,8 @@
 #import "SDLSyncMsgVersion.h"
 #import "SDLVehicleType.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLRegisterAppInterfaceResponse
 
 - (instancetype)init {
@@ -23,140 +25,142 @@
     return self;
 }
 
-- (void)setSyncMsgVersion:(SDLSyncMsgVersion *)syncMsgVersion {
+- (void)setSyncMsgVersion:(nullable SDLSyncMsgVersion *)syncMsgVersion {
     [parameters sdl_setObject:syncMsgVersion forName:SDLNameSyncMessageVersion];
 }
 
-- (SDLSyncMsgVersion *)syncMsgVersion {
+- (nullable SDLSyncMsgVersion *)syncMsgVersion {
     return [parameters sdl_objectForName:SDLNameSyncMessageVersion ofClass:SDLSyncMsgVersion.class];
 }
 
-- (void)setLanguage:(SDLLanguage)language {
+- (void)setLanguage:(nullable SDLLanguage)language {
     [parameters sdl_setObject:language forName:SDLNameLanguage];
 }
 
-- (SDLLanguage)language {
+- (nullable SDLLanguage)language {
     return [parameters sdl_objectForName:SDLNameLanguage];
 }
 
-- (void)setHmiDisplayLanguage:(SDLLanguage)hmiDisplayLanguage {
+- (void)setHmiDisplayLanguage:(nullable SDLLanguage)hmiDisplayLanguage {
     [parameters sdl_setObject:hmiDisplayLanguage forName:SDLNameHMIDisplayLanguage];
 }
 
-- (SDLLanguage)hmiDisplayLanguage {
+- (nullable SDLLanguage)hmiDisplayLanguage {
     return [parameters sdl_objectForName:SDLNameHMIDisplayLanguage];
 }
 
-- (void)setDisplayCapabilities:(SDLDisplayCapabilities *)displayCapabilities {
+- (void)setDisplayCapabilities:(nullable SDLDisplayCapabilities *)displayCapabilities {
     [parameters sdl_setObject:displayCapabilities forName:SDLNameDisplayCapabilities];
 }
 
-- (SDLDisplayCapabilities *)displayCapabilities {
+- (nullable SDLDisplayCapabilities *)displayCapabilities {
     return [parameters sdl_objectForName:SDLNameDisplayCapabilities ofClass:SDLDisplayCapabilities.class];
 }
 
-- (void)setButtonCapabilities:(NSMutableArray<SDLButtonCapabilities *> *)buttonCapabilities {
+- (void)setButtonCapabilities:(nullable NSMutableArray<SDLButtonCapabilities *> *)buttonCapabilities {
     [parameters sdl_setObject:buttonCapabilities forName:SDLNameButtonCapabilities];
 }
 
-- (NSMutableArray<SDLButtonCapabilities *> *)buttonCapabilities {
+- (nullable NSMutableArray<SDLButtonCapabilities *> *)buttonCapabilities {
     return [parameters sdl_objectsForName:SDLNameButtonCapabilities ofClass:SDLButtonCapabilities.class];
 }
 
-- (void)setSoftButtonCapabilities:(NSMutableArray<SDLSoftButtonCapabilities *> *)softButtonCapabilities {
+- (void)setSoftButtonCapabilities:(nullable NSMutableArray<SDLSoftButtonCapabilities *> *)softButtonCapabilities {
     [parameters sdl_setObject:softButtonCapabilities forName:SDLNameSoftButtonCapabilities];
 }
 
-- (NSMutableArray<SDLSoftButtonCapabilities *> *)softButtonCapabilities {
+- (nullable NSMutableArray<SDLSoftButtonCapabilities *> *)softButtonCapabilities {
     return [parameters sdl_objectsForName:SDLNameSoftButtonCapabilities ofClass:SDLSoftButtonCapabilities.class];
 }
 
-- (void)setPresetBankCapabilities:(SDLPresetBankCapabilities *)presetBankCapabilities {
+- (void)setPresetBankCapabilities:(nullable SDLPresetBankCapabilities *)presetBankCapabilities {
     [parameters sdl_setObject:presetBankCapabilities forName:SDLNamePresetBankCapabilities];
 }
 
-- (SDLPresetBankCapabilities *)presetBankCapabilities {
+- (nullable SDLPresetBankCapabilities *)presetBankCapabilities {
     return [parameters sdl_objectForName:SDLNamePresetBankCapabilities ofClass:SDLPresetBankCapabilities.class];
 }
 
-- (void)setHmiZoneCapabilities:(NSMutableArray<SDLHMIZoneCapabilities> *)hmiZoneCapabilities {
+- (void)setHmiZoneCapabilities:(nullable NSMutableArray<SDLHMIZoneCapabilities> *)hmiZoneCapabilities {
     [parameters sdl_setObject:hmiZoneCapabilities forName:SDLNameHMIZoneCapabilities];
 }
 
-- (NSMutableArray<SDLHMIZoneCapabilities> *)hmiZoneCapabilities {
+- (nullable NSMutableArray<SDLHMIZoneCapabilities> *)hmiZoneCapabilities {
     return [parameters sdl_objectForName:SDLNameHMIZoneCapabilities];
 }
 
-- (void)setSpeechCapabilities:(NSMutableArray<SDLSpeechCapabilities> *)speechCapabilities {
+- (void)setSpeechCapabilities:(nullable NSMutableArray<SDLSpeechCapabilities> *)speechCapabilities {
     [parameters sdl_setObject:speechCapabilities forName:SDLNameSpeechCapabilities];
 }
 
-- (NSMutableArray<SDLSpeechCapabilities> *)speechCapabilities {
+- (nullable NSMutableArray<SDLSpeechCapabilities> *)speechCapabilities {
     return [parameters sdl_objectForName:SDLNameSpeechCapabilities];
 }
 
-- (void)setPrerecordedSpeech:(NSMutableArray<SDLPrerecordedSpeech> *)prerecordedSpeech {
+- (void)setPrerecordedSpeech:(nullable NSMutableArray<SDLPrerecordedSpeech> *)prerecordedSpeech {
     [parameters sdl_setObject:prerecordedSpeech forName:SDLNamePrerecordedSpeech];
 }
 
-- (NSMutableArray<SDLPrerecordedSpeech> *)prerecordedSpeech {
+- (nullable NSMutableArray<SDLPrerecordedSpeech> *)prerecordedSpeech {
     return [parameters sdl_objectForName:SDLNamePrerecordedSpeech];
 }
 
-- (void)setVrCapabilities:(NSMutableArray<SDLVRCapabilities> *)vrCapabilities {
+- (void)setVrCapabilities:(nullable NSMutableArray<SDLVRCapabilities> *)vrCapabilities {
     [parameters sdl_setObject:vrCapabilities forName:SDLNameVRCapabilities];
 }
 
-- (NSMutableArray<SDLVRCapabilities> *)vrCapabilities {
+- (nullable NSMutableArray<SDLVRCapabilities> *)vrCapabilities {
     return [parameters sdl_objectForName:SDLNameVRCapabilities];
 }
 
-- (void)setAudioPassThruCapabilities:(NSMutableArray<SDLAudioPassThruCapabilities *> *)audioPassThruCapabilities {
+- (void)setAudioPassThruCapabilities:(nullable NSMutableArray<SDLAudioPassThruCapabilities *> *)audioPassThruCapabilities {
     [parameters sdl_setObject:audioPassThruCapabilities forName:SDLNameAudioPassThruCapabilities];
 }
 
-- (NSMutableArray<SDLAudioPassThruCapabilities *> *)audioPassThruCapabilities {
+- (nullable NSMutableArray<SDLAudioPassThruCapabilities *> *)audioPassThruCapabilities {
     return [parameters sdl_objectsForName:SDLNameAudioPassThruCapabilities ofClass:SDLAudioPassThruCapabilities.class];
 }
 
-- (void)setVehicleType:(SDLVehicleType *)vehicleType {
+- (void)setVehicleType:(nullable SDLVehicleType *)vehicleType {
     [parameters sdl_setObject:vehicleType forName:SDLNameVehicleType];
 }
 
-- (SDLVehicleType *)vehicleType {
+- (nullable SDLVehicleType *)vehicleType {
     return [parameters sdl_objectForName:SDLNameVehicleType ofClass:SDLVehicleType.class];
 }
 
-- (void)setSupportedDiagModes:(NSMutableArray<NSNumber<SDLInt> *> *)supportedDiagModes {
+- (void)setSupportedDiagModes:(nullable NSMutableArray<NSNumber<SDLInt> *> *)supportedDiagModes {
     [parameters sdl_setObject:supportedDiagModes forName:SDLNameSupportedDiagnosticModes];
 }
 
-- (NSMutableArray<NSNumber<SDLInt> *> *)supportedDiagModes {
+- (nullable NSMutableArray<NSNumber<SDLInt> *> *)supportedDiagModes {
     return [parameters sdl_objectForName:SDLNameSupportedDiagnosticModes];
 }
 
-- (void)setHmiCapabilities:(SDLHMICapabilities *)hmiCapabilities {
+- (void)setHmiCapabilities:(nullable SDLHMICapabilities *)hmiCapabilities {
     [parameters sdl_setObject:hmiCapabilities forName:SDLNameHMICapabilities];
 }
 
-- (SDLHMICapabilities *)hmiCapabilities {
+- (nullable SDLHMICapabilities *)hmiCapabilities {
     return [parameters sdl_objectForName:SDLNameHMICapabilities ofClass:SDLHMICapabilities.class];
 }
 
-- (void)setSdlVersion:(NSString *)sdlVersion {
+- (void)setSdlVersion:(nullable NSString *)sdlVersion {
     [parameters sdl_setObject:sdlVersion forName:SDLNameSDLVersion];
 }
 
-- (NSString *)sdlVersion {
+- (nullable NSString *)sdlVersion {
     return [parameters sdl_objectForName:SDLNameSDLVersion];
 }
 
-- (void)setSystemSoftwareVersion:(NSString *)systemSoftwareVersion {
+- (void)setSystemSoftwareVersion:(nullable NSString *)systemSoftwareVersion {
     [parameters sdl_setObject:systemSoftwareVersion forName:SDLNameSystemSoftwareVersion];
 }
 
-- (NSString *)systemSoftwareVersion {
+- (nullable NSString *)systemSoftwareVersion {
     return [parameters sdl_objectForName:SDLNameSystemSoftwareVersion];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLRequestHandler.h b/SmartDeviceLink/SDLRequestHandler.h
index d05cdfd38..64ee67b48 100644
--- a/SmartDeviceLink/SDLRequestHandler.h
+++ b/SmartDeviceLink/SDLRequestHandler.h
@@ -17,7 +17,7 @@ NS_ASSUME_NONNULL_BEGIN
 /**
  *  The handler that is added to any RPC implementing this protocol.
  */
-@property (copy, nonatomic) SDLRPCNotificationHandler handler;
+@property (nullable, copy, nonatomic) SDLRPCNotificationHandler handler;
 
 /**
  *  A special init function on any RPC implementing this protocol.
@@ -26,7 +26,7 @@ NS_ASSUME_NONNULL_BEGIN
  *
  *  @return An instance of the class implementing this protocol.
  */
-- (instancetype)initWithHandler:(SDLRPCNotificationHandler)handler;
+- (instancetype)initWithHandler:(nullable SDLRPCNotificationHandler)handler;
 
 @end
 
diff --git a/SmartDeviceLink/SDLResetGlobalProperties.h b/SmartDeviceLink/SDLResetGlobalProperties.h
index 697ad8cb8..7c842e5c1 100644
--- a/SmartDeviceLink/SDLResetGlobalProperties.h
+++ b/SmartDeviceLink/SDLResetGlobalProperties.h
@@ -22,6 +22,9 @@
  * Since SmartDeviceLink 1.0
  * See SetGlobalProperties
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLResetGlobalProperties : SDLRPCRequest
 
 - (instancetype)initWithProperties:(NSArray<SDLGlobalProperty> *)properties;
@@ -30,6 +33,8 @@
  * @abstract An array of one or more GlobalProperty enumeration elements
  * indicating which global properties to reset to their default value
  */
-@property (strong) NSMutableArray<SDLGlobalProperty> *properties;
+@property (strong, nonatomic) NSMutableArray<SDLGlobalProperty> *properties;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLResetGlobalProperties.m b/SmartDeviceLink/SDLResetGlobalProperties.m
index 5725793d0..8c7b317b4 100644
--- a/SmartDeviceLink/SDLResetGlobalProperties.m
+++ b/SmartDeviceLink/SDLResetGlobalProperties.m
@@ -8,6 +8,8 @@
 #import "SDLGlobalProperty.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLResetGlobalProperties
 
 - (instancetype)init {
@@ -36,3 +38,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLResetGlobalPropertiesResponse.h b/SmartDeviceLink/SDLResetGlobalPropertiesResponse.h
index eda1b2628..23a043cd6 100644
--- a/SmartDeviceLink/SDLResetGlobalPropertiesResponse.h
+++ b/SmartDeviceLink/SDLResetGlobalPropertiesResponse.h
@@ -9,6 +9,11 @@
  *
  * Since SmartDeviceLink 1.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLResetGlobalPropertiesResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLResetGlobalPropertiesResponse.m b/SmartDeviceLink/SDLResetGlobalPropertiesResponse.m
index 739fd189b..4db428b7b 100644
--- a/SmartDeviceLink/SDLResetGlobalPropertiesResponse.m
+++ b/SmartDeviceLink/SDLResetGlobalPropertiesResponse.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLResetGlobalPropertiesResponse
 
 - (instancetype)init {
@@ -16,3 +18,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLScreenParams.h b/SmartDeviceLink/SDLScreenParams.h
index 6236181cf..23c7a16a6 100644
--- a/SmartDeviceLink/SDLScreenParams.h
+++ b/SmartDeviceLink/SDLScreenParams.h
@@ -6,10 +6,13 @@
 @class SDLImageResolution;
 @class SDLTouchEventCapabilities;
 
+NS_ASSUME_NONNULL_BEGIN
 
 @interface SDLScreenParams : SDLRPCStruct
 
-@property (strong) SDLImageResolution *resolution;
-@property (strong) SDLTouchEventCapabilities *touchEventAvailable;
+@property (strong, nonatomic) SDLImageResolution *resolution;
+@property (nullable, strong, nonatomic) SDLTouchEventCapabilities *touchEventAvailable;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLScreenParams.m b/SmartDeviceLink/SDLScreenParams.m
index 7bed14548..d531dfadd 100644
--- a/SmartDeviceLink/SDLScreenParams.m
+++ b/SmartDeviceLink/SDLScreenParams.m
@@ -8,6 +8,8 @@
 #import "SDLNames.h"
 #import "SDLTouchEventCapabilities.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLScreenParams
 
 - (void)setResolution:(SDLImageResolution *)resolution {
@@ -18,12 +20,14 @@
     return [store sdl_objectForName:SDLNameResolution ofClass:SDLImageResolution.class];
 }
 
-- (void)setTouchEventAvailable:(SDLTouchEventCapabilities *)touchEventAvailable {
+- (void)setTouchEventAvailable:(nullable SDLTouchEventCapabilities *)touchEventAvailable {
     [store sdl_setObject:touchEventAvailable forName:SDLNameTouchEventAvailable];
 }
 
-- (SDLTouchEventCapabilities *)touchEventAvailable {
+- (nullable SDLTouchEventCapabilities *)touchEventAvailable {
     return [store sdl_objectForName:SDLNameTouchEventAvailable ofClass:SDLTouchEventCapabilities.class];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLScrollableMessage.h b/SmartDeviceLink/SDLScrollableMessage.h
index c06f1911e..87ed0be98 100644
--- a/SmartDeviceLink/SDLScrollableMessage.h
+++ b/SmartDeviceLink/SDLScrollableMessage.h
@@ -15,11 +15,14 @@
  * <b>HMILevel needs to be FULL</b>
  * <p>
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLScrollableMessage : SDLRPCRequest
 
 - (instancetype)initWithMessage:(NSString *)message;
 
-- (instancetype)initWithMessage:(NSString *)message timeout:(UInt16)timeout softButtons:(NSArray<SDLSoftButton *> *)softButtons;
+- (instancetype)initWithMessage:(NSString *)message timeout:(UInt16)timeout softButtons:(nullable NSArray<SDLSoftButton *> *)softButtons;
 
 /**
  * @abstract A Body of text that can include newlines and tabs
@@ -28,7 +31,7 @@
  *            <p>
  *            <b>Notes: </b>Maxlength=500
  */
-@property (strong) NSString *scrollableMessageBody;
+@property (strong, nonatomic) NSString *scrollableMessageBody;
 /**
  * @abstract Gets/Sets an App defined timeout. Indicates how long of a timeout in milliseconds from the
  * last action
@@ -36,7 +39,7 @@
  *            <p>
  *            <b>Notes</b>:Minval=0; Maxval=65535;Default=30000
  */
-@property (strong) NSNumber<SDLInt> *timeout;
+@property (nullable, strong, nonatomic) NSNumber<SDLInt> *timeout;
 /**
  * @abstract Gets/Sets App defined SoftButtons.If omitted on supported displays, only the
  * system defined "Close" SoftButton will be displayed
@@ -45,6 +48,8 @@
  *            <p>
  *            <b>Notes: </b>Minsize=0, Maxsize=8
  */
-@property (strong) NSMutableArray<SDLSoftButton *> *softButtons;
+@property (nullable, strong, nonatomic) NSMutableArray<SDLSoftButton *> *softButtons;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLScrollableMessage.m b/SmartDeviceLink/SDLScrollableMessage.m
index 251807034..f156e5453 100644
--- a/SmartDeviceLink/SDLScrollableMessage.m
+++ b/SmartDeviceLink/SDLScrollableMessage.m
@@ -8,6 +8,8 @@
 #import "SDLNames.h"
 #import "SDLSoftButton.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLScrollableMessage
 
 - (instancetype)init {
@@ -16,7 +18,7 @@
     return self;
 }
 
-- (instancetype)initWithMessage:(NSString *)message timeout:(UInt16)timeout softButtons:(NSArray<SDLSoftButton *> *)softButtons {
+- (instancetype)initWithMessage:(NSString *)message timeout:(UInt16)timeout softButtons:(nullable NSArray<SDLSoftButton *> *)softButtons {
     self = [self initWithMessage:message];
     if (!self) {
         return nil;
@@ -47,20 +49,22 @@
     return [parameters sdl_objectForName:SDLNameScrollableMessageBody];
 }
 
-- (void)setTimeout:(NSNumber<SDLInt> *)timeout {
+- (void)setTimeout:(nullable NSNumber<SDLInt> *)timeout {
     [parameters sdl_setObject:timeout forName:SDLNameTimeout];
 }
 
-- (NSNumber<SDLInt> *)timeout {
+- (nullable NSNumber<SDLInt> *)timeout {
     return [parameters sdl_objectForName:SDLNameTimeout];
 }
 
-- (void)setSoftButtons:(NSMutableArray<SDLSoftButton *> *)softButtons {
+- (void)setSoftButtons:(nullable NSMutableArray<SDLSoftButton *> *)softButtons {
     [parameters sdl_setObject:softButtons forName:SDLNameSoftButtons];
 }
 
-- (NSMutableArray<SDLSoftButton *> *)softButtons {
+- (nullable NSMutableArray<SDLSoftButton *> *)softButtons {
     return [parameters sdl_objectsForName:SDLNameSoftButtons ofClass:SDLSoftButton.class];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLScrollableMessageResponse.h b/SmartDeviceLink/SDLScrollableMessageResponse.h
index 516415468..4f6d17a8a 100644
--- a/SmartDeviceLink/SDLScrollableMessageResponse.h
+++ b/SmartDeviceLink/SDLScrollableMessageResponse.h
@@ -9,6 +9,11 @@
  *
  * Since SmartDeviceLink 2.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLScrollableMessageResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSendLocation.h b/SmartDeviceLink/SDLSendLocation.h
index bff1859ce..c2d007604 100644
--- a/SmartDeviceLink/SDLSendLocation.h
+++ b/SmartDeviceLink/SDLSendLocation.h
@@ -11,80 +11,84 @@
 #import "SDLImage.h"
 #import "SDLOasisAddress.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLSendLocation : SDLRPCRequest
 
-- (instancetype)initWithLongitude:(double)longitude latitude:(double)latitude locationName:(NSString *)locationName locationDescription:(NSString *)locationDescription address:(NSArray<NSString *> *)address phoneNumber:(NSString *)phoneNumber image:(SDLImage *)image;
+- (instancetype)initWithLongitude:(double)longitude latitude:(double)latitude locationName:(nullable NSString *)locationName locationDescription:(nullable NSString *)locationDescription address:(nullable NSArray<NSString *> *)address phoneNumber:(nullable NSString *)phoneNumber image:(nullable SDLImage *)image;
 
-- (instancetype)initWithLongitude:(double)longitude latitude:(double)latitude locationName:(NSString *)locationName locationDescription:(NSString *)locationDescription displayAddressLines:(NSArray<NSString *> *)displayAddressLines phoneNumber:(NSString *)phoneNumber image:(SDLImage *)image deliveryMode:(SDLDeliveryMode)deliveryMode timeStamp:(SDLDateTime *)timeStamp address:(SDLOasisAddress *)address;
+- (instancetype)initWithLongitude:(double)longitude latitude:(double)latitude locationName:(nullable NSString *)locationName locationDescription:(nullable NSString *)locationDescription displayAddressLines:(nullable NSArray<NSString *> *)displayAddressLines phoneNumber:(nullable NSString *)phoneNumber image:(nullable SDLImage *)image deliveryMode:(nullable SDLDeliveryMode)deliveryMode timeStamp:(nullable SDLDateTime *)timeStamp address:(nullable SDLOasisAddress *)address;
 
 /**
  * The longitudinal coordinate of the location.
  *
  * Float, Required, -180.0 - 180.0
  */
-@property (copy, nonatomic) NSNumber<SDLFloat> *longitudeDegrees;
+@property (nullable, copy, nonatomic) NSNumber<SDLFloat> *longitudeDegrees;
 
 /**
  * The latitudinal coordinate of the location.
  *
  * Float, Required, -90.0 - 90.0
  */
-@property (copy, nonatomic) NSNumber<SDLFloat> *latitudeDegrees;
+@property (nullable, copy, nonatomic) NSNumber<SDLFloat> *latitudeDegrees;
 
 /**
  * Name / title of intended location
  *
  * Optional, Maxlength = 500 char
  */
-@property (copy, nonatomic) NSString *locationName;
+@property (nullable, copy, nonatomic) NSString *locationName;
 
 /**
  * Description of the intended location / establishment
  *
  * Optional, MaxLength = 500 char
  */
-@property (copy, nonatomic) NSString *locationDescription;
+@property (nullable, copy, nonatomic) NSString *locationDescription;
 
 /**
  * Location address for display purposes only
  *
  * Contains String, Optional, Max Array Length = 4, Max String Length = 500
  */
-@property (copy, nonatomic) NSArray<NSString *> *addressLines;
+@property (nullable, copy, nonatomic) NSArray<NSString *> *addressLines;
 
 /**
  * Phone number of intended location / establishment
  *
  * Optional, Max Length = 500
  */
-@property (copy, nonatomic) NSString *phoneNumber;
+@property (nullable, copy, nonatomic) NSString *phoneNumber;
 
 /**
  * Image / icon of intended location
  *
  * Optional
  */
-@property (strong, nonatomic) SDLImage *locationImage;
+@property (nullable, strong, nonatomic) SDLImage *locationImage;
 
 /**
  * Mode in which the sendLocation request is sent
  *
  * Optional
  */
-@property (strong, nonatomic) SDLDeliveryMode deliveryMode;
+@property (nullable, strong, nonatomic) SDLDeliveryMode deliveryMode;
 
 /**
  * Arrival time of Location. If multiple SendLocations are sent, this will be used for sorting as well.
  *
  * Optional
  */
-@property (strong, nonatomic) SDLDateTime *timeStamp;
+@property (nullable, strong, nonatomic) SDLDateTime *timeStamp;
 
 /**
  * Address to be used for setting destination
  *
  * Optional
  */
-@property (strong, nonatomic) SDLOasisAddress *address;
+@property (nullable, strong, nonatomic) SDLOasisAddress *address;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSendLocation.m b/SmartDeviceLink/SDLSendLocation.m
index 15be8bc86..115c30a34 100644
--- a/SmartDeviceLink/SDLSendLocation.m
+++ b/SmartDeviceLink/SDLSendLocation.m
@@ -7,6 +7,7 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
 
 @implementation SDLSendLocation
 
@@ -19,11 +20,11 @@
     return self;
 }
 
-- (instancetype)initWithLongitude:(double)longitude latitude:(double)latitude locationName:(NSString *)locationName locationDescription:(NSString *)locationDescription address:(NSArray<NSString *> *)address phoneNumber:(NSString *)phoneNumber image:(SDLImage *)image {
+- (instancetype)initWithLongitude:(double)longitude latitude:(double)latitude locationName:(nullable NSString *)locationName locationDescription:(nullable NSString *)locationDescription address:(nullable NSArray<NSString *> *)address phoneNumber:(nullable NSString *)phoneNumber image:(nullable SDLImage *)image {
     return [self initWithLongitude:longitude latitude:latitude locationName:locationName locationDescription:locationDescription displayAddressLines:address phoneNumber:phoneNumber image:image deliveryMode:nil timeStamp:nil address:nil];
 }
 
-- (instancetype)initWithLongitude:(double)longitude latitude:(double)latitude locationName:(NSString *)locationName locationDescription:(NSString *)locationDescription displayAddressLines:(NSArray<NSString *> *)displayAddressLines phoneNumber:(NSString *)phoneNumber image:(SDLImage *)image deliveryMode:(SDLDeliveryMode)deliveryMode timeStamp:(SDLDateTime *)timeStamp address:(SDLOasisAddress *)address {
+- (instancetype)initWithLongitude:(double)longitude latitude:(double)latitude locationName:(nullable NSString *)locationName locationDescription:(nullable NSString *)locationDescription displayAddressLines:(nullable NSArray<NSString *> *)displayAddressLines phoneNumber:(nullable NSString *)phoneNumber image:(nullable SDLImage *)image deliveryMode:(nullable SDLDeliveryMode)deliveryMode timeStamp:(nullable SDLDateTime *)timeStamp address:(nullable SDLOasisAddress *)address {
     self = [self init];
     if (!self) {
         return nil;
@@ -43,84 +44,86 @@
     return self;
 }
 
-- (void)setLongitudeDegrees:(NSNumber<SDLFloat> *)longitudeDegrees {
+- (void)setLongitudeDegrees:(nullable NSNumber<SDLFloat> *)longitudeDegrees {
     [parameters sdl_setObject:longitudeDegrees forName:SDLNameLongitudeDegrees];
 }
 
-- (NSNumber<SDLFloat> *)longitudeDegrees {
+- (nullable NSNumber<SDLFloat> *)longitudeDegrees {
     return [parameters sdl_objectForName:SDLNameLongitudeDegrees];
 }
 
-- (void)setLatitudeDegrees:(NSNumber<SDLFloat> *)latitudeDegrees {
+- (void)setLatitudeDegrees:(nullable NSNumber<SDLFloat> *)latitudeDegrees {
     [parameters sdl_setObject:latitudeDegrees forName:SDLNameLatitudeDegrees];
 }
 
-- (NSNumber<SDLFloat> *)latitudeDegrees {
+- (nullable NSNumber<SDLFloat> *)latitudeDegrees {
     return [parameters sdl_objectForName:SDLNameLatitudeDegrees];
 }
 
-- (void)setLocationName:(NSString *)locationName {
+- (void)setLocationName:(nullable NSString *)locationName {
     [parameters sdl_setObject:locationName forName:SDLNameLocationName];
 }
 
-- (NSString *)locationName {
+- (nullable NSString *)locationName {
     return [parameters sdl_objectForName:SDLNameLocationName];
 }
 
-- (void)setAddressLines:(NSArray<NSString *> *)addressLines {
+- (void)setAddressLines:(nullable NSArray<NSString *> *)addressLines {
     [parameters sdl_setObject:addressLines forName:SDLNameAddressLines];
 }
 
-- (NSString *)locationDescription {
+- (nullable NSString *)locationDescription {
     return [parameters sdl_objectForName:SDLNameLocationDescription];
 }
 
-- (void)setLocationDescription:(NSString *)locationDescription {
+- (void)setLocationDescription:(nullable NSString *)locationDescription {
     [parameters sdl_setObject:locationDescription forName:SDLNameLocationDescription];
 }
 
-- (NSArray<NSString *> *)addressLines {
+- (nullable NSArray<NSString *> *)addressLines {
     return [parameters sdl_objectForName:SDLNameAddressLines];
 }
 
-- (void)setPhoneNumber:(NSString *)phoneNumber {
+- (void)setPhoneNumber:(nullable NSString *)phoneNumber {
     [parameters sdl_setObject:phoneNumber forName:SDLNamePhoneNumber];
 }
 
-- (NSString *)phoneNumber {
+- (nullable NSString *)phoneNumber {
     return [parameters sdl_objectForName:SDLNamePhoneNumber];
 }
 
-- (void)setLocationImage:(SDLImage *)locationImage {
+- (void)setLocationImage:(nullable SDLImage *)locationImage {
     [parameters sdl_setObject:locationImage forName:SDLNameLocationImage];
 }
 
-- (SDLImage *)locationImage {
+- (nullable SDLImage *)locationImage {
     return [parameters sdl_objectForName:SDLNameLocationImage ofClass:SDLImage.class];
 }
 
-- (void)setDeliveryMode:(SDLDeliveryMode)deliveryMode {
+- (void)setDeliveryMode:(nullable SDLDeliveryMode)deliveryMode {
     [parameters sdl_setObject:deliveryMode forName:SDLNameDeliveryMode];
 }
 
-- (SDLDeliveryMode)deliveryMode {
+- (nullable SDLDeliveryMode)deliveryMode {
     return [parameters sdl_objectForName:SDLNameDeliveryMode];
 }
 
-- (void)setTimeStamp:(SDLDateTime *)timeStamp {
+- (void)setTimeStamp:(nullable SDLDateTime *)timeStamp {
     [parameters sdl_setObject:timeStamp forName:SDLNameLocationTimeStamp];
 }
 
-- (SDLDateTime *)timeStamp {
+- (nullable SDLDateTime *)timeStamp {
     return [parameters sdl_objectForName:SDLNameLocationTimeStamp ofClass:SDLDateTime.class];
 }
 
-- (void)setAddress:(SDLOasisAddress *)address {
+- (void)setAddress:(nullable SDLOasisAddress *)address {
     [parameters sdl_setObject:address forName:SDLNameAddress];
 }
 
-- (SDLOasisAddress *)address {
+- (nullable SDLOasisAddress *)address {
     return [parameters sdl_objectForName:SDLNameAddress ofClass:SDLOasisAddress.class];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSendLocationResponse.h b/SmartDeviceLink/SDLSendLocationResponse.h
index 35fc2eca1..8059bc1b2 100644
--- a/SmartDeviceLink/SDLSendLocationResponse.h
+++ b/SmartDeviceLink/SDLSendLocationResponse.h
@@ -4,6 +4,10 @@
 
 #import "SDLRPCResponse.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLSendLocationResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSendLocationResponse.m b/SmartDeviceLink/SDLSendLocationResponse.m
index 4cac6e167..3b03a5a67 100644
--- a/SmartDeviceLink/SDLSendLocationResponse.m
+++ b/SmartDeviceLink/SDLSendLocationResponse.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLSendLocationResponse
 
 - (instancetype)init {
@@ -19,3 +21,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSetAppIcon.h b/SmartDeviceLink/SDLSetAppIcon.h
index 37fd11974..2b99843c6 100644
--- a/SmartDeviceLink/SDLSetAppIcon.h
+++ b/SmartDeviceLink/SDLSetAppIcon.h
@@ -11,6 +11,9 @@
  *
  * Since SmartDeviceLink 2.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLSetAppIcon : SDLRPCRequest
 
 - (instancetype)initWithFileName:(NSString *)fileName;
@@ -22,6 +25,8 @@
  *            <p>
  *            <b>Notes: </b>Maxlength=500
  */
-@property (strong) NSString *syncFileName;
+@property (strong, nonatomic) NSString *syncFileName;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSetAppIconResponse.h b/SmartDeviceLink/SDLSetAppIconResponse.h
index 28c818782..ba189dc4d 100644
--- a/SmartDeviceLink/SDLSetAppIconResponse.h
+++ b/SmartDeviceLink/SDLSetAppIconResponse.h
@@ -7,6 +7,11 @@
 /** SDLSetAppIconResponse is sent, when SDLSetAppIcon has been called.
  * Since<b>SmartDeviceLink 2.0</b>
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLSetAppIconResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSetAppIconResponse.m b/SmartDeviceLink/SDLSetAppIconResponse.m
index d99aa7990..2a0b72793 100644
--- a/SmartDeviceLink/SDLSetAppIconResponse.m
+++ b/SmartDeviceLink/SDLSetAppIconResponse.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLSetAppIconResponse
 
 - (instancetype)init {
@@ -16,3 +18,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSetDisplayLayout.h b/SmartDeviceLink/SDLSetDisplayLayout.h
index e60b6219b..c2097d804 100644
--- a/SmartDeviceLink/SDLSetDisplayLayout.h
+++ b/SmartDeviceLink/SDLSetDisplayLayout.h
@@ -12,6 +12,9 @@
  *
  * Since SmartDeviceLink 2.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLSetDisplayLayout : SDLRPCRequest
 
 - (instancetype)initWithPredefinedLayout:(SDLPredefinedLayout)predefinedLayout;
@@ -25,6 +28,8 @@
  * include: "ONSCREEN_PRESETS" Custom screen containing app-defined onscreen
  * presets. Currently defined for GEN2
  */
-@property (strong) NSString *displayLayout;
+@property (strong, nonatomic) NSString *displayLayout;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSetDisplayLayout.m b/SmartDeviceLink/SDLSetDisplayLayout.m
index b4c802834..21c8627f1 100644
--- a/SmartDeviceLink/SDLSetDisplayLayout.m
+++ b/SmartDeviceLink/SDLSetDisplayLayout.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLSetDisplayLayout
 
 - (instancetype)init {
@@ -39,3 +41,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSetDisplayLayoutResponse.h b/SmartDeviceLink/SDLSetDisplayLayoutResponse.h
index 1beff1419..edacb17ed 100644
--- a/SmartDeviceLink/SDLSetDisplayLayoutResponse.h
+++ b/SmartDeviceLink/SDLSetDisplayLayoutResponse.h
@@ -13,11 +13,16 @@
  *
  * Since SmartDeviceLink 2.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLSetDisplayLayoutResponse : SDLRPCResponse
 
-@property (strong) SDLDisplayCapabilities *displayCapabilities;
-@property (strong) NSMutableArray<SDLButtonCapabilities *> *buttonCapabilities;
-@property (strong) NSMutableArray<SDLSoftButtonCapabilities *> *softButtonCapabilities;
-@property (strong) SDLPresetBankCapabilities *presetBankCapabilities;
+@property (nullable, strong, nonatomic) SDLDisplayCapabilities *displayCapabilities;
+@property (nullable, strong, nonatomic) NSMutableArray<SDLButtonCapabilities *> *buttonCapabilities;
+@property (nullable, strong, nonatomic) NSMutableArray<SDLSoftButtonCapabilities *> *softButtonCapabilities;
+@property (nullable, strong, nonatomic) SDLPresetBankCapabilities *presetBankCapabilities;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSetDisplayLayoutResponse.m b/SmartDeviceLink/SDLSetDisplayLayoutResponse.m
index fc4213384..2d1795413 100644
--- a/SmartDeviceLink/SDLSetDisplayLayoutResponse.m
+++ b/SmartDeviceLink/SDLSetDisplayLayoutResponse.m
@@ -11,6 +11,8 @@
 #import "SDLPresetBankCapabilities.h"
 #import "SDLSoftButtonCapabilities.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLSetDisplayLayoutResponse
 
 - (instancetype)init {
@@ -19,36 +21,38 @@
     return self;
 }
 
-- (void)setDisplayCapabilities:(SDLDisplayCapabilities *)displayCapabilities {
+- (void)setDisplayCapabilities:(nullable SDLDisplayCapabilities *)displayCapabilities {
     [parameters sdl_setObject:displayCapabilities forName:SDLNameDisplayCapabilities];
 }
 
-- (SDLDisplayCapabilities *)displayCapabilities {
+- (nullable SDLDisplayCapabilities *)displayCapabilities {
     return [parameters sdl_objectForName:SDLNameDisplayCapabilities ofClass:SDLDisplayCapabilities.class];
 }
 
-- (void)setButtonCapabilities:(NSMutableArray<SDLButtonCapabilities *> *)buttonCapabilities {
+- (void)setButtonCapabilities:(nullable NSMutableArray<SDLButtonCapabilities *> *)buttonCapabilities {
     [parameters sdl_setObject:buttonCapabilities forName:SDLNameButtonCapabilities];
 }
 
-- (NSMutableArray<SDLButtonCapabilities *> *)buttonCapabilities {
+- (nullable NSMutableArray<SDLButtonCapabilities *> *)buttonCapabilities {
     return [parameters sdl_objectsForName:SDLNameButtonCapabilities ofClass:SDLButtonCapabilities.class];
 }
 
-- (void)setSoftButtonCapabilities:(NSMutableArray<SDLSoftButtonCapabilities *> *)softButtonCapabilities {
+- (void)setSoftButtonCapabilities:(nullable NSMutableArray<SDLSoftButtonCapabilities *> *)softButtonCapabilities {
     [parameters sdl_setObject:softButtonCapabilities forName:SDLNameSoftButtonCapabilities];
 }
 
-- (NSMutableArray<SDLSoftButtonCapabilities *> *)softButtonCapabilities {
+- (nullable NSMutableArray<SDLSoftButtonCapabilities *> *)softButtonCapabilities {
     return [parameters sdl_objectsForName:SDLNameSoftButtonCapabilities ofClass:SDLSoftButtonCapabilities.class];
 }
 
-- (void)setPresetBankCapabilities:(SDLPresetBankCapabilities *)presetBankCapabilities {
+- (void)setPresetBankCapabilities:(nullable SDLPresetBankCapabilities *)presetBankCapabilities {
     [parameters sdl_setObject:presetBankCapabilities forName:SDLNamePresetBankCapabilities];
 }
 
-- (SDLPresetBankCapabilities *)presetBankCapabilities {
+- (nullable SDLPresetBankCapabilities *)presetBankCapabilities {
     return [parameters sdl_objectForName:SDLNamePresetBankCapabilities ofClass:SDLPresetBankCapabilities.class];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSetGlobalProperties.h b/SmartDeviceLink/SDLSetGlobalProperties.h
index f4110e031..95c803bae 100644
--- a/SmartDeviceLink/SDLSetGlobalProperties.h
+++ b/SmartDeviceLink/SDLSetGlobalProperties.h
@@ -18,13 +18,16 @@
  * Since SmartDeviceLink 1.0
  * See SDLResetGlobalProperties
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLSetGlobalProperties : SDLRPCRequest
 
-- (instancetype)initWithHelpText:(NSString *)helpText timeoutText:(NSString *)timeoutText;
+- (instancetype)initWithHelpText:(nullable NSString *)helpText timeoutText:(nullable NSString *)timeoutText;
 
-- (instancetype)initWithHelpText:(NSString *)helpText timeoutText:(NSString *)timeoutText vrHelpTitle:(NSString *)vrHelpTitle vrHelp:(NSArray<SDLVRHelpItem *> *)vrHelp;
+- (instancetype)initWithHelpText:(nullable NSString *)helpText timeoutText:(nullable NSString *)timeoutText vrHelpTitle:(nullable NSString *)vrHelpTitle vrHelp:(nullable NSArray<SDLVRHelpItem *> *)vrHelp;
 
-- (instancetype)initWithHelpText:(NSString *)helpText timeoutText:(NSString *)timeoutText vrHelpTitle:(NSString *)vrHelpTitle vrHelp:(NSArray<SDLVRHelpItem *> *)vrHelp menuTitle:(NSString *)menuTitle menuIcon:(SDLImage *)menuIcon keyboardProperties:(SDLKeyboardProperties *)keyboardProperties;
+- (instancetype)initWithHelpText:(nullable NSString *)helpText timeoutText:(nullable NSString *)timeoutText vrHelpTitle:(nullable NSString *)vrHelpTitle vrHelp:(nullable NSArray<SDLVRHelpItem *> *)vrHelp menuTitle:(nullable NSString *)menuTitle menuIcon:(nullable SDLImage *)menuIcon keyboardProperties:(nullable SDLKeyboardProperties *)keyboardProperties;
 
 /**
  * @abstract Sets a Vector<TTSChunk> for Help Prompt that Array of one or more
@@ -39,14 +42,14 @@
  *            <li>Only optional it timeoutPrompt has been specified</li>
  *            </ul>
  */
-@property (strong) NSMutableArray<SDLTTSChunk *> *helpPrompt;
+@property (strong, nonatomic, nullable) NSMutableArray<SDLTTSChunk *> *helpPrompt;
 /**
  * @abstract A Vector<TTSChunk> for Timeout Prompt representing Array of one or
  * more TTSChunk elements specifying the help prompt used in an interaction
  * started by PTT
  *
  */
-@property (strong) NSMutableArray<SDLTTSChunk *> *timeoutPrompt;
+@property (strong, nonatomic, nullable) NSMutableArray<SDLTTSChunk *> *timeoutPrompt;
 /**
  * @abstract Sets a voice recognition Help Title
  *
@@ -62,7 +65,7 @@
  *            </ul>
  * @since SmartDeviceLink 2.0
  */
-@property (strong) NSString *vrHelpTitle;
+@property (strong, nonatomic, nullable) NSString *vrHelpTitle;
 /**
  * @abstract Sets the items listed in the VR help screen used in an interaction
  * started by PTT
@@ -83,9 +86,11 @@
  *            </ul>
  * @since SmartDeviceLink 2.0
  */
-@property (strong) NSMutableArray<SDLVRHelpItem *> *vrHelp;
-@property (strong) NSString *menuTitle;
-@property (strong) SDLImage *menuIcon;
-@property (strong) SDLKeyboardProperties *keyboardProperties;
+@property (strong, nonatomic, nullable) NSMutableArray<SDLVRHelpItem *> *vrHelp;
+@property (strong, nonatomic, nullable) NSString *menuTitle;
+@property (strong, nonatomic, nullable) SDLImage *menuIcon;
+@property (strong, nonatomic, nullable) SDLKeyboardProperties *keyboardProperties;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSetGlobalProperties.m b/SmartDeviceLink/SDLSetGlobalProperties.m
index e3348d410..8cc46bdc1 100644
--- a/SmartDeviceLink/SDLSetGlobalProperties.m
+++ b/SmartDeviceLink/SDLSetGlobalProperties.m
@@ -11,6 +11,7 @@
 #import "SDLTTSChunk.h"
 #import "SDLVRHelpItem.h"
 
+NS_ASSUME_NONNULL_BEGIN
 
 @implementation SDLSetGlobalProperties
 
@@ -20,15 +21,15 @@
     return self;
 }
 
-- (instancetype)initWithHelpText:(NSString *)helpText timeoutText:(NSString *)timeoutText {
+- (instancetype)initWithHelpText:(nullable NSString *)helpText timeoutText:(nullable NSString *)timeoutText {
     return [self initWithHelpText:helpText timeoutText:timeoutText vrHelpTitle:nil vrHelp:nil];
 }
 
-- (instancetype)initWithHelpText:(NSString *)helpText timeoutText:(NSString *)timeoutText vrHelpTitle:(NSString *)vrHelpTitle vrHelp:(NSArray<SDLVRHelpItem *> *)vrHelp {
+- (instancetype)initWithHelpText:(nullable NSString *)helpText timeoutText:(nullable NSString *)timeoutText vrHelpTitle:(nullable NSString *)vrHelpTitle vrHelp:(nullable NSArray<SDLVRHelpItem *> *)vrHelp {
     return [self initWithHelpText:helpText timeoutText:timeoutText vrHelpTitle:vrHelpTitle vrHelp:vrHelp menuTitle:nil menuIcon:nil keyboardProperties:nil];
 }
 
-- (instancetype)initWithHelpText:(NSString *)helpText timeoutText:(NSString *)timeoutText vrHelpTitle:(NSString *)vrHelpTitle vrHelp:(NSArray<SDLVRHelpItem *> *)vrHelp menuTitle:(NSString *)menuTitle menuIcon:(SDLImage *)menuIcon keyboardProperties:(SDLKeyboardProperties *)keyboardProperties {
+- (instancetype)initWithHelpText:(nullable NSString *)helpText timeoutText:(nullable NSString *)timeoutText vrHelpTitle:(nullable NSString *)vrHelpTitle vrHelp:(nullable NSArray<SDLVRHelpItem *> *)vrHelp menuTitle:(nullable NSString *)menuTitle menuIcon:(nullable SDLImage *)menuIcon keyboardProperties:(nullable SDLKeyboardProperties *)keyboardProperties {
     self = [self init];
     if (!self) {
         return nil;
@@ -45,61 +46,62 @@
     return self;
 }
 
-
-- (void)setHelpPrompt:(NSMutableArray<SDLTTSChunk *> *)helpPrompt {
+- (void)setHelpPrompt:(nullable NSMutableArray<SDLTTSChunk *> *)helpPrompt {
     [parameters sdl_setObject:helpPrompt forName:SDLNameHelpPrompt];
 }
 
-- (NSMutableArray<SDLTTSChunk *> *)helpPrompt {
+- (nullable NSMutableArray<SDLTTSChunk *> *)helpPrompt {
     return [parameters sdl_objectsForName:SDLNameHelpPrompt ofClass:SDLTTSChunk.class];
 }
 
-- (void)setTimeoutPrompt:(NSMutableArray<SDLTTSChunk *> *)timeoutPrompt {
+- (void)setTimeoutPrompt:(nullable NSMutableArray<SDLTTSChunk *> *)timeoutPrompt {
     [parameters sdl_setObject:timeoutPrompt forName:SDLNameTimeoutPrompt];
 }
 
-- (NSMutableArray<SDLTTSChunk *> *)timeoutPrompt {
+- (nullable NSMutableArray<SDLTTSChunk *> *)timeoutPrompt {
     return [parameters sdl_objectsForName:SDLNameTimeoutPrompt ofClass:SDLTTSChunk.class];
 }
 
-- (void)setVrHelpTitle:(NSString *)vrHelpTitle {
+- (void)setVrHelpTitle:(nullable NSString *)vrHelpTitle {
     [parameters sdl_setObject:vrHelpTitle forName:SDLNameVRHelpTitle];
 }
 
-- (NSString *)vrHelpTitle {
+- (nullable NSString *)vrHelpTitle {
     return [parameters sdl_objectForName:SDLNameVRHelpTitle];
 }
 
-- (void)setVrHelp:(NSMutableArray<SDLVRHelpItem *> *)vrHelp {
+- (void)setVrHelp:(nullable NSMutableArray<SDLVRHelpItem *> *)vrHelp {
     [parameters sdl_setObject:vrHelp forName:SDLNameVRHelp];
 }
 
-- (NSMutableArray<SDLVRHelpItem *> *)vrHelp {
+- (nullable NSMutableArray<SDLVRHelpItem *> *)vrHelp {
     return [parameters sdl_objectsForName:SDLNameVRHelp ofClass:SDLVRHelpItem.class];
 }
 
-- (void)setMenuTitle:(NSString *)menuTitle {
+- (void)setMenuTitle:(nullable NSString *)menuTitle {
     [parameters sdl_setObject:menuTitle forName:SDLNameMenuTitle];
 }
 
-- (NSString *)menuTitle {
+- (nullable NSString *)menuTitle {
     return [parameters sdl_objectForName:SDLNameMenuTitle];
 }
 
-- (void)setMenuIcon:(SDLImage *)menuIcon {
+- (void)setMenuIcon:(nullable SDLImage *)menuIcon {
     [parameters sdl_setObject:menuIcon forName:SDLNameMenuIcon];
 }
 
-- (SDLImage *)menuIcon {
+- (nullable SDLImage *)menuIcon {
     return [parameters sdl_objectForName:SDLNameMenuIcon ofClass:SDLImage.class];
 }
 
-- (void)setKeyboardProperties:(SDLKeyboardProperties *)keyboardProperties {
+- (void)setKeyboardProperties:(nullable SDLKeyboardProperties *)keyboardProperties {
     [parameters sdl_setObject:keyboardProperties forName:SDLNameKeyboardProperties];
 }
 
-- (SDLKeyboardProperties *)keyboardProperties {
+- (nullable SDLKeyboardProperties *)keyboardProperties {
     return [parameters sdl_objectForName:SDLNameKeyboardProperties ofClass:SDLKeyboardProperties.class];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSetGlobalPropertiesResponse.h b/SmartDeviceLink/SDLSetGlobalPropertiesResponse.h
index a5dd82139..f41991d53 100644
--- a/SmartDeviceLink/SDLSetGlobalPropertiesResponse.h
+++ b/SmartDeviceLink/SDLSetGlobalPropertiesResponse.h
@@ -9,6 +9,11 @@
  *
  * Since SmartDeviceLink 1.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLSetGlobalPropertiesResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSetGlobalPropertiesResponse.m b/SmartDeviceLink/SDLSetGlobalPropertiesResponse.m
index 7b292c071..9da9719cc 100644
--- a/SmartDeviceLink/SDLSetGlobalPropertiesResponse.m
+++ b/SmartDeviceLink/SDLSetGlobalPropertiesResponse.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLSetGlobalPropertiesResponse
 
 - (instancetype)init {
@@ -16,3 +18,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSetMediaClockTimer.h b/SmartDeviceLink/SDLSetMediaClockTimer.h
index 09ba6344a..f561299f5 100644
--- a/SmartDeviceLink/SDLSetMediaClockTimer.h
+++ b/SmartDeviceLink/SDLSetMediaClockTimer.h
@@ -17,6 +17,9 @@
  *
  * Since SmartDeviceLink 1.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLSetMediaClockTimer : SDLRPCRequest
 
 - (instancetype)initWithUpdateMode:(SDLUpdateMode)updateMode hours:(UInt8)hours minutes:(UInt8)minutes seconds:(UInt8)seconds;
@@ -35,13 +38,13 @@
  *            <li>Will be ignored for PAUSE/RESUME and CLEAR</li>
  *            </ul>
  */
-@property (strong) SDLStartTime *startTime;
+@property (strong, nonatomic, nullable) SDLStartTime *startTime;
 /**
  * @abstract An END time of type SDLStartTime, specifying hour, minute, second values
  *
  * @discussion An SDLStartTime object with specifying hour, minute, second values
  */
-@property (strong) SDLStartTime *endTime;
+@property (strong, nonatomic, nullable) SDLStartTime *endTime;
 /**
  * @abstract The media clock/timer update mode (COUNTUP/COUNTDOWN/PAUSE/RESUME)
  *
@@ -55,6 +58,8 @@
  *            the timer's value when it was paused</li>
  *            </ul>
  */
-@property (strong) SDLUpdateMode updateMode;
+@property (strong, nonatomic) SDLUpdateMode updateMode;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSetMediaClockTimer.m b/SmartDeviceLink/SDLSetMediaClockTimer.m
index af3062d4b..793fd1493 100644
--- a/SmartDeviceLink/SDLSetMediaClockTimer.m
+++ b/SmartDeviceLink/SDLSetMediaClockTimer.m
@@ -8,6 +8,8 @@
 #import "SDLNames.h"
 #import "SDLStartTime.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLSetMediaClockTimer
 
 - (instancetype)init {
@@ -39,19 +41,19 @@
     return self;
 }
 
-- (void)setStartTime:(SDLStartTime *)startTime {
+- (void)setStartTime:(nullable SDLStartTime *)startTime {
     [parameters sdl_setObject:startTime forName:SDLNameStartTime];
 }
 
-- (SDLStartTime *)startTime {
+- (nullable SDLStartTime *)startTime {
     return [parameters sdl_objectForName:SDLNameStartTime ofClass:SDLStartTime.class];
 }
 
-- (void)setEndTime:(SDLStartTime *)endTime {
+- (void)setEndTime:(nullable SDLStartTime *)endTime {
     [parameters sdl_setObject:endTime forName:SDLNameEndTime];
 }
 
-- (SDLStartTime *)endTime {
+- (nullable SDLStartTime *)endTime {
     return [parameters sdl_objectForName:SDLNameEndTime ofClass:SDLStartTime.class];
 }
 
@@ -64,3 +66,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSetMediaClockTimerResponse.h b/SmartDeviceLink/SDLSetMediaClockTimerResponse.h
index d1adbda4d..54a599821 100644
--- a/SmartDeviceLink/SDLSetMediaClockTimerResponse.h
+++ b/SmartDeviceLink/SDLSetMediaClockTimerResponse.h
@@ -9,6 +9,11 @@
  *
  * Since SmartDeviceLink 1.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLSetMediaClockTimerResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSetMediaClockTimerResponse.m b/SmartDeviceLink/SDLSetMediaClockTimerResponse.m
index d851e900b..f293e7d79 100644
--- a/SmartDeviceLink/SDLSetMediaClockTimerResponse.m
+++ b/SmartDeviceLink/SDLSetMediaClockTimerResponse.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLSetMediaClockTimerResponse
 
 - (instancetype)init {
@@ -16,3 +18,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLShow.h b/SmartDeviceLink/SDLShow.h
index 8b4c11137..fb6c16411 100644
--- a/SmartDeviceLink/SDLShow.h
+++ b/SmartDeviceLink/SDLShow.h
@@ -30,16 +30,18 @@
  * Since SmartDeviceLink 1.0
  * See SDLAlert SDLSetMediaClockTimer
  */
-@interface SDLShow : SDLRPCRequest
 
-- (instancetype)initWithMainField1:(NSString *)mainField1 mainField2:(NSString *)mainField2 alignment:(SDLTextAlignment)alignment;
+NS_ASSUME_NONNULL_BEGIN
+
+@interface SDLShow : SDLRPCRequest
 
-- (instancetype)initWithMainField1:(NSString *)mainField1 mainField2:(NSString *)mainField2 mainField3:(NSString *)mainField3 mainField4:(NSString *)mainField4 alignment:(SDLTextAlignment)alignment;
+- (instancetype)initWithMainField1:(nullable NSString *)mainField1 mainField2:(nullable NSString *)mainField2 alignment:(nullable SDLTextAlignment)alignment;
 
-- (instancetype)initWithMainField1:(NSString *)mainField1 mainField2:(NSString *)mainField2 alignment:(SDLTextAlignment)alignment statusBar:(NSString *)statusBar mediaClock:(NSString *)mediaClock mediaTrack:(NSString *)mediaTrack;
+- (instancetype)initWithMainField1:(nullable NSString *)mainField1 mainField2:(nullable NSString *)mainField2 mainField3:(nullable NSString *)mainField3 mainField4:(nullable NSString *)mainField4 alignment:(nullable SDLTextAlignment)alignment;
 
-- (instancetype)initWithMainField1:(NSString *)mainField1 mainField2:(NSString *)mainField2 mainField3:(NSString *)mainField3 mainField4:(NSString *)mainField4 alignment:(SDLTextAlignment)alignment statusBar:(NSString *)statusBar mediaClock:(NSString *)mediaClock mediaTrack:(NSString *)mediaTrack graphic:(SDLImage *)graphic softButtons:(NSArray<SDLSoftButton *> *)softButtons customPresets:(NSArray<NSString *> *)customPresets;
+- (instancetype)initWithMainField1:(nullable NSString *)mainField1 mainField2:(nullable NSString *)mainField2 alignment:(nullable SDLTextAlignment)alignment statusBar:(nullable NSString *)statusBar mediaClock:(nullable NSString *)mediaClock mediaTrack:(nullable NSString *)mediaTrack;
 
+- (instancetype)initWithMainField1:(nullable NSString *)mainField1 mainField2:(nullable NSString *)mainField2 mainField3:(nullable NSString *)mainField3 mainField4:(nullable NSString *)mainField4 alignment:(nullable SDLTextAlignment)alignment statusBar:(nullable NSString *)statusBar mediaClock:(nullable NSString *)mediaClock mediaTrack:(nullable NSString *)mediaTrack graphic:(nullable SDLImage *)graphic softButtons:(nullable NSArray<SDLSoftButton *> *)softButtons customPresets:(nullable NSArray<NSString *> *)customPresets;
 
 /**
  * @abstract The text displayed in a single-line display, or in the upper display
@@ -56,7 +58,7 @@
  *            cleared</li>
  *            </ul>
  */
-@property (strong) NSString *mainField1;
+@property (strong, nonatomic, nullable) NSString *mainField1;
 /**
  * @abstract The text displayed on the second display line of a two-line display
  *
@@ -74,7 +76,7 @@
  *            <li>Maxlength = 500</li>
  *            </ul>
  */
-@property (strong) NSString *mainField2;
+@property (strong, nonatomic, nullable) NSString *mainField2;
 /**
  * @abstract The text displayed on the first display line of the second page
  *
@@ -93,7 +95,7 @@
  *            </ul>
  * @since SmartDeviceLink 2.0
  */
-@property (strong) NSString *mainField3;
+@property (strong, nonatomic, nullable) NSString *mainField3;
 /**
  * @abstract The text displayed on the second display line of the second page
  *
@@ -112,7 +114,7 @@
  *            </ul>
  * @since SmartDeviceLink 2.0
  */
-@property (strong) NSString *mainField4;
+@property (strong, nonatomic, nullable) NSString *mainField4;
 /**
  * @abstract The alignment that Specifies how mainField1 and mainField2 text
  * should be aligned on display
@@ -128,7 +130,7 @@
  *            <li>Has no effect with navigation display</li>
  *            </ul>
  */
-@property (strong) SDLTextAlignment alignment;
+@property (strong, nonatomic, nullable) SDLTextAlignment alignment;
 /**
  * @abstract Text in the Status Bar
  *
@@ -146,7 +148,7 @@
  *            parameter is ignored</li>
  *            </ul>
  */
-@property (strong) NSString *statusBar;
+@property (strong, nonatomic, nullable) NSString *statusBar;
 /**
  * @abstract This property is deprecated use SetMediaClockTimer instead.
  * <p> The value for the MediaClock field using a format described in the
@@ -163,7 +165,7 @@
  *            will not display anything)</li>
  *            </ul>
  */
-@property (strong) NSString *mediaClock;
+@property (strong, nonatomic, nullable) NSString *mediaClock;
 /**
  * @abstract The text in the track field
  *
@@ -176,7 +178,7 @@
  *            <li>This field is only valid for media applications on navigation displays</li>
  *            </ul>
  */
-@property (strong) NSString *mediaTrack;
+@property (strong, nonatomic, nullable) NSString *mediaTrack;
 /**
  * @abstract An image to be shown on supported displays
  *
@@ -186,7 +188,7 @@
  *            graphic shall not change<br/>
  * @since SmartDeviceLink 2.0
  */
-@property (strong) SDLImage *graphic;
+@property (strong, nonatomic, nullable) SDLImage *graphic;
 /**
  * @abstract An image to be shown on supported displays
  *
@@ -196,7 +198,7 @@
  *            graphic shall not change<br/>
  * @since SmartDeviceLink 2.0
  */
-@property (strong) SDLImage *secondaryGraphic;
+@property (strong, nonatomic, nullable) SDLImage *secondaryGraphic;
 /**
  * @abstract The the Soft buttons defined by the App
  *
@@ -213,7 +215,7 @@
  *
  * @since SmartDeviceLink 2.0
  */
-@property (strong) NSMutableArray<SDLSoftButton *> *softButtons;
+@property (strong, nonatomic, nullable) NSMutableArray<SDLSoftButton *> *softButtons;
 /**
  * @abstract The Custom Presets defined by the App
  *
@@ -227,6 +229,8 @@
  *            </ul>
  * @since SmartDeviceLink 2.0
  */
-@property (strong) NSMutableArray<NSString *> *customPresets;
+@property (strong, nonatomic, nullable) NSMutableArray<NSString *> *customPresets;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLShow.m b/SmartDeviceLink/SDLShow.m
index 24663f145..39977b640 100644
--- a/SmartDeviceLink/SDLShow.m
+++ b/SmartDeviceLink/SDLShow.m
@@ -9,6 +9,7 @@
 #import "SDLNames.h"
 #import "SDLSoftButton.h"
 
+NS_ASSUME_NONNULL_BEGIN
 
 @implementation SDLShow
 
@@ -18,19 +19,19 @@
     return self;
 }
 
-- (instancetype)initWithMainField1:(NSString *)mainField1 mainField2:(NSString *)mainField2 alignment:(SDLTextAlignment)alignment {
+- (instancetype)initWithMainField1:(nullable NSString *)mainField1 mainField2:(nullable NSString *)mainField2 alignment:(nullable SDLTextAlignment)alignment {
     return [self initWithMainField1:mainField1 mainField2:mainField2 mainField3:nil mainField4:nil alignment:alignment];
 }
 
-- (instancetype)initWithMainField1:(NSString *)mainField1 mainField2:(NSString *)mainField2 mainField3:(NSString *)mainField3 mainField4:(NSString *)mainField4 alignment:(SDLTextAlignment)alignment {
+- (instancetype)initWithMainField1:(nullable NSString *)mainField1 mainField2:(nullable NSString *)mainField2 mainField3:(nullable NSString *)mainField3 mainField4:(nullable NSString *)mainField4 alignment:(nullable SDLTextAlignment)alignment {
     return [self initWithMainField1:mainField1 mainField2:mainField2 mainField3:mainField3 mainField4:mainField4 alignment:alignment statusBar:nil mediaClock:nil mediaTrack:nil graphic:nil softButtons:nil customPresets:nil];
 }
 
-- (instancetype)initWithMainField1:(NSString *)mainField1 mainField2:(NSString *)mainField2 alignment:(SDLTextAlignment)alignment statusBar:(NSString *)statusBar mediaClock:(NSString *)mediaClock mediaTrack:(NSString *)mediaTrack {
+- (instancetype)initWithMainField1:(nullable NSString *)mainField1 mainField2:(nullable NSString *)mainField2 alignment:(nullable SDLTextAlignment)alignment statusBar:(nullable NSString *)statusBar mediaClock:(nullable NSString *)mediaClock mediaTrack:(nullable NSString *)mediaTrack {
     return [self initWithMainField1:mainField1 mainField2:mainField2 mainField3:nil mainField4:nil alignment:alignment statusBar:statusBar mediaClock:mediaClock mediaTrack:mediaTrack graphic:nil softButtons:nil customPresets:nil];
 }
 
-- (instancetype)initWithMainField1:(NSString *)mainField1 mainField2:(NSString *)mainField2 mainField3:(NSString *)mainField3 mainField4:(NSString *)mainField4 alignment:(SDLTextAlignment)alignment statusBar:(NSString *)statusBar mediaClock:(NSString *)mediaClock mediaTrack:(NSString *)mediaTrack graphic:(SDLImage *)graphic softButtons:(NSArray<SDLSoftButton *> *)softButtons customPresets:(NSArray<NSString *> *)customPresets {
+- (instancetype)initWithMainField1:(nullable NSString *)mainField1 mainField2:(nullable NSString *)mainField2 mainField3:(nullable NSString *)mainField3 mainField4:(nullable NSString *)mainField4 alignment:(nullable SDLTextAlignment)alignment statusBar:(nullable NSString *)statusBar mediaClock:(nullable NSString *)mediaClock mediaTrack:(nullable NSString *)mediaTrack graphic:(nullable SDLImage *)graphic softButtons:(nullable NSArray<SDLSoftButton *> *)softButtons customPresets:(nullable NSArray<NSString *> *)customPresets {
     self = [self init];
     if (!self) {
         return nil;
@@ -51,100 +52,102 @@
     return self;
 }
 
-- (void)setMainField1:(NSString *)mainField1 {
+- (void)setMainField1:(nullable NSString *)mainField1 {
     [parameters sdl_setObject:mainField1 forName:SDLNameMainField1];
 }
 
-- (NSString *)mainField1 {
+- (nullable NSString *)mainField1 {
     return [parameters sdl_objectForName:SDLNameMainField1];
 }
 
-- (void)setMainField2:(NSString *)mainField2 {
+- (void)setMainField2:(nullable NSString *)mainField2 {
     [parameters sdl_setObject:mainField2 forName:SDLNameMainField2];
 }
 
-- (NSString *)mainField2 {
+- (nullable NSString *)mainField2 {
     return [parameters sdl_objectForName:SDLNameMainField2];
 }
 
-- (void)setMainField3:(NSString *)mainField3 {
+- (void)setMainField3:(nullable NSString *)mainField3 {
     [parameters sdl_setObject:mainField3 forName:SDLNameMainField3];
 }
 
-- (NSString *)mainField3 {
+- (nullable NSString *)mainField3 {
     return [parameters sdl_objectForName:SDLNameMainField3];
 }
 
-- (void)setMainField4:(NSString *)mainField4 {
+- (void)setMainField4:(nullable NSString *)mainField4 {
     [parameters sdl_setObject:mainField4 forName:SDLNameMainField4];
 }
 
-- (NSString *)mainField4 {
+- (nullable NSString *)mainField4 {
     return [parameters sdl_objectForName:SDLNameMainField4];
 }
 
-- (void)setAlignment:(SDLTextAlignment)alignment {
+- (void)setAlignment:(nullable SDLTextAlignment)alignment {
     [parameters sdl_setObject:alignment forName:SDLNameAlignment];
 }
 
-- (SDLTextAlignment)alignment {
+- (nullable SDLTextAlignment)alignment {
     return [parameters sdl_objectForName:SDLNameAlignment];
 }
 
-- (void)setStatusBar:(NSString *)statusBar {
+- (void)setStatusBar:(nullable NSString *)statusBar {
     [parameters sdl_setObject:statusBar forName:SDLNameStatusBar];
 }
 
-- (NSString *)statusBar {
+- (nullable NSString *)statusBar {
     return [parameters sdl_objectForName:SDLNameStatusBar];
 }
 
-- (void)setMediaClock:(NSString *)mediaClock {
+- (void)setMediaClock:(nullable NSString *)mediaClock {
     [parameters sdl_setObject:mediaClock forName:SDLNameMediaClock];
 }
 
-- (NSString *)mediaClock {
+- (nullable NSString *)mediaClock {
     return [parameters sdl_objectForName:SDLNameMediaClock];
 }
 
-- (void)setMediaTrack:(NSString *)mediaTrack {
+- (void)setMediaTrack:(nullable NSString *)mediaTrack {
     [parameters sdl_setObject:mediaTrack forName:SDLNameMediaTrack];
 }
 
-- (NSString *)mediaTrack {
+- (nullable NSString *)mediaTrack {
     return [parameters sdl_objectForName:SDLNameMediaTrack];
 }
 
-- (void)setGraphic:(SDLImage *)graphic {
+- (void)setGraphic:(nullable SDLImage *)graphic {
     [parameters sdl_setObject:graphic forName:SDLNameGraphic];
 }
 
-- (SDLImage *)graphic {
+- (nullable SDLImage *)graphic {
     return [parameters sdl_objectForName:SDLNameGraphic ofClass:SDLImage.class];
 }
 
-- (void)setSecondaryGraphic:(SDLImage *)secondaryGraphic {
+- (void)setSecondaryGraphic:(nullable SDLImage *)secondaryGraphic {
     [parameters sdl_setObject:secondaryGraphic forName:SDLNameSecondaryGraphic];
 }
 
-- (SDLImage *)secondaryGraphic {
+- (nullable SDLImage *)secondaryGraphic {
     return [parameters sdl_objectForName:SDLNameSecondaryGraphic ofClass:SDLImage.class];
 }
 
-- (void)setSoftButtons:(NSMutableArray<SDLSoftButton *> *)softButtons {
+- (void)setSoftButtons:(nullable NSMutableArray<SDLSoftButton *> *)softButtons {
     [parameters sdl_setObject:softButtons forName:SDLNameSoftButtons];
 }
 
-- (NSMutableArray<SDLSoftButton *> *)softButtons {
+- (nullable NSMutableArray<SDLSoftButton *> *)softButtons {
     return [parameters sdl_objectsForName:SDLNameSoftButtons ofClass:SDLSoftButton.class];
 }
 
-- (void)setCustomPresets:(NSMutableArray<NSString *> *)customPresets {
+- (void)setCustomPresets:(nullable NSMutableArray<NSString *> *)customPresets {
     [parameters sdl_setObject:customPresets forName:SDLNameCustomPresets];
 }
 
-- (NSMutableArray<NSString *> *)customPresets {
+- (nullable NSMutableArray<NSString *> *)customPresets {
     return [parameters sdl_objectForName:SDLNameCustomPresets];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLShowConstantTBT.h b/SmartDeviceLink/SDLShowConstantTBT.h
index 48601b1e8..90604befa 100644
--- a/SmartDeviceLink/SDLShowConstantTBT.h
+++ b/SmartDeviceLink/SDLShowConstantTBT.h
@@ -12,20 +12,25 @@
  *<p>
  * @since SmartDeviceLink 2.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLShowConstantTBT : SDLRPCRequest
 
-- (instancetype)initWithNavigationText1:(NSString *)navigationText1 navigationText2:(NSString *)navigationText2 eta:(NSString *)eta timeToDestination:(NSString *)timeToDestination totalDistance:(NSString *)totalDistance turnIcon:(SDLImage *)turnIcon nextTurnIcon:(SDLImage *)nextTurnIcon distanceToManeuver:(double)distanceToManeuver distanceToManeuverScale:(double)distanceToManeuverScale maneuverComplete:(BOOL)maneuverComplete softButtons:(NSArray<SDLSoftButton *> *)softButtons;
+- (instancetype)initWithNavigationText1:(nullable NSString *)navigationText1 navigationText2:(nullable NSString *)navigationText2 eta:(nullable NSString *)eta timeToDestination:(nullable NSString *)timeToDestination totalDistance:(nullable NSString *)totalDistance turnIcon:(nullable SDLImage *)turnIcon nextTurnIcon:(nullable SDLImage *)nextTurnIcon distanceToManeuver:(double)distanceToManeuver distanceToManeuverScale:(double)distanceToManeuverScale maneuverComplete:(BOOL)maneuverComplete softButtons:(nullable NSArray<SDLSoftButton *> *)softButtons;
 
-@property (strong) NSString *navigationText1;
-@property (strong) NSString *navigationText2;
-@property (strong) NSString *eta;
-@property (strong) NSString *timeToDestination;
-@property (strong) NSString *totalDistance;
-@property (strong) SDLImage *turnIcon;
-@property (strong) SDLImage *nextTurnIcon;
-@property (strong) NSNumber<SDLFloat> *distanceToManeuver;
-@property (strong) NSNumber<SDLFloat> *distanceToManeuverScale;
-@property (strong) NSNumber<SDLBool> *maneuverComplete;
-@property (strong) NSMutableArray<SDLSoftButton *> *softButtons;
+@property (strong, nonatomic, nullable) NSString *navigationText1;
+@property (strong, nonatomic, nullable) NSString *navigationText2;
+@property (strong, nonatomic, nullable) NSString *eta;
+@property (strong, nonatomic, nullable) NSString *timeToDestination;
+@property (strong, nonatomic, nullable) NSString *totalDistance;
+@property (strong, nonatomic, nullable) SDLImage *turnIcon;
+@property (strong, nonatomic, nullable) SDLImage *nextTurnIcon;
+@property (strong, nonatomic, nullable) NSNumber<SDLFloat> *distanceToManeuver;
+@property (strong, nonatomic, nullable) NSNumber<SDLFloat> *distanceToManeuverScale;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *maneuverComplete;
+@property (strong, nonatomic, nullable) NSMutableArray<SDLSoftButton *> *softButtons;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLShowConstantTBT.m b/SmartDeviceLink/SDLShowConstantTBT.m
index 3b9b68224..f410b85af 100644
--- a/SmartDeviceLink/SDLShowConstantTBT.m
+++ b/SmartDeviceLink/SDLShowConstantTBT.m
@@ -9,6 +9,8 @@
 #import "SDLNames.h"
 #import "SDLSoftButton.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLShowConstantTBT
 
 - (instancetype)init {
@@ -17,7 +19,7 @@
     return self;
 }
 
-- (instancetype)initWithNavigationText1:(NSString *)navigationText1 navigationText2:(NSString *)navigationText2 eta:(NSString *)eta timeToDestination:(NSString *)timeToDestination totalDistance:(NSString *)totalDistance turnIcon:(SDLImage *)turnIcon nextTurnIcon:(SDLImage *)nextTurnIcon distanceToManeuver:(double)distanceToManeuver distanceToManeuverScale:(double)distanceToManeuverScale maneuverComplete:(BOOL)maneuverComplete softButtons:(NSArray<SDLSoftButton *> *)softButtons {
+- (instancetype)initWithNavigationText1:(nullable NSString *)navigationText1 navigationText2:(nullable NSString *)navigationText2 eta:(nullable NSString *)eta timeToDestination:(nullable NSString *)timeToDestination totalDistance:(nullable NSString *)totalDistance turnIcon:(nullable SDLImage *)turnIcon nextTurnIcon:(nullable SDLImage *)nextTurnIcon distanceToManeuver:(double)distanceToManeuver distanceToManeuverScale:(double)distanceToManeuverScale maneuverComplete:(BOOL)maneuverComplete softButtons:(nullable NSArray<SDLSoftButton *> *)softButtons {
     self = [self init];
     if (!self) {
         return nil;
@@ -38,92 +40,94 @@
     return self;
 }
 
-- (void)setNavigationText1:(NSString *)navigationText1 {
+- (void)setNavigationText1:(nullable NSString *)navigationText1 {
     [parameters sdl_setObject:navigationText1 forName:SDLNameNavigationText1];
 }
 
-- (NSString *)navigationText1 {
+- (nullable NSString *)navigationText1 {
     return [parameters sdl_objectForName:SDLNameNavigationText1];
 }
 
-- (void)setNavigationText2:(NSString *)navigationText2 {
+- (void)setNavigationText2:(nullable NSString *)navigationText2 {
     [parameters sdl_setObject:navigationText2 forName:SDLNameNavigationText2];
 }
 
-- (NSString *)navigationText2 {
+- (nullable NSString *)navigationText2 {
     return [parameters sdl_objectForName:SDLNameNavigationText2];
 }
 
-- (void)setEta:(NSString *)eta {
+- (void)setEta:(nullable NSString *)eta {
     [parameters sdl_setObject:eta forName:SDLNameETA];
 }
 
-- (NSString *)eta {
+- (nullable NSString *)eta {
     return [parameters sdl_objectForName:SDLNameETA];
 }
 
-- (void)setTimeToDestination:(NSString *)timeToDestination {
+- (void)setTimeToDestination:(nullable NSString *)timeToDestination {
     [parameters sdl_setObject:timeToDestination forName:SDLNameTimeToDestination];
 }
 
-- (NSString *)timeToDestination {
+- (nullable NSString *)timeToDestination {
     return [parameters sdl_objectForName:SDLNameTimeToDestination];
 }
 
-- (void)setTotalDistance:(NSString *)totalDistance {
+- (void)setTotalDistance:(nullable NSString *)totalDistance {
     [parameters sdl_setObject:totalDistance forName:SDLNameTotalDistance];
 }
 
-- (NSString *)totalDistance {
+- (nullable NSString *)totalDistance {
     return [parameters sdl_objectForName:SDLNameTotalDistance];
 }
 
-- (void)setTurnIcon:(SDLImage *)turnIcon {
+- (void)setTurnIcon:(nullable SDLImage *)turnIcon {
     [parameters sdl_setObject:turnIcon forName:SDLNameTurnIcon];
 }
 
-- (SDLImage *)turnIcon {
+- (nullable SDLImage *)turnIcon {
     return [parameters sdl_objectForName:SDLNameTurnIcon ofClass:SDLImage.class];
 }
 
-- (void)setNextTurnIcon:(SDLImage *)nextTurnIcon {
+- (void)setNextTurnIcon:(nullable SDLImage *)nextTurnIcon {
     [parameters sdl_setObject:nextTurnIcon forName:SDLNameNextTurnIcon];
 }
 
-- (SDLImage *)nextTurnIcon {
+- (nullable SDLImage *)nextTurnIcon {
     return [parameters sdl_objectForName:SDLNameNextTurnIcon ofClass:SDLImage.class];
 }
 
-- (void)setDistanceToManeuver:(NSNumber<SDLFloat> *)distanceToManeuver {
+- (void)setDistanceToManeuver:(nullable NSNumber<SDLFloat> *)distanceToManeuver {
     [parameters sdl_setObject:distanceToManeuver forName:SDLNameDistanceToManeuver];
 }
 
-- (NSNumber<SDLFloat> *)distanceToManeuver {
+- (nullable NSNumber<SDLFloat> *)distanceToManeuver {
     return [parameters sdl_objectForName:SDLNameDistanceToManeuver];
 }
 
-- (void)setDistanceToManeuverScale:(NSNumber<SDLFloat> *)distanceToManeuverScale {
+- (void)setDistanceToManeuverScale:(nullable NSNumber<SDLFloat> *)distanceToManeuverScale {
     [parameters sdl_setObject:distanceToManeuverScale forName:SDLNameDistanceToManeuverScale];
 }
 
-- (NSNumber<SDLFloat> *)distanceToManeuverScale {
+- (nullable NSNumber<SDLFloat> *)distanceToManeuverScale {
     return [parameters sdl_objectForName:SDLNameDistanceToManeuverScale];
 }
 
-- (void)setManeuverComplete:(NSNumber<SDLBool> *)maneuverComplete {
+- (void)setManeuverComplete:(nullable NSNumber<SDLBool> *)maneuverComplete {
     [parameters sdl_setObject:maneuverComplete forName:SDLNameManeuverComplete];
 }
 
-- (NSNumber<SDLBool> *)maneuverComplete {
+- (nullable NSNumber<SDLBool> *)maneuverComplete {
     return [parameters sdl_objectForName:SDLNameManeuverComplete];
 }
 
-- (void)setSoftButtons:(NSMutableArray<SDLSoftButton *> *)softButtons {
+- (void)setSoftButtons:(nullable NSMutableArray<SDLSoftButton *> *)softButtons {
     [parameters sdl_setObject:softButtons forName:SDLNameSoftButtons];
 }
 
-- (NSMutableArray<SDLSoftButton *> *)softButtons {
+- (nullable NSMutableArray<SDLSoftButton *> *)softButtons {
     return [parameters sdl_objectsForName:SDLNameSoftButtons ofClass:SDLSoftButton.class];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLShowConstantTBTResponse.h b/SmartDeviceLink/SDLShowConstantTBTResponse.h
index 8af3a9f23..b6c196734 100644
--- a/SmartDeviceLink/SDLShowConstantTBTResponse.h
+++ b/SmartDeviceLink/SDLShowConstantTBTResponse.h
@@ -7,6 +7,11 @@
 /** SDLShowConstantTBTResponse is sent, when SDLShowConstantTBT has been called.
  * Since<b>SmartDeviceLink 2.0</b>
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLShowConstantTBTResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLShowConstantTBTResponse.m b/SmartDeviceLink/SDLShowConstantTBTResponse.m
index a68cc5caf..40a9c9bd9 100644
--- a/SmartDeviceLink/SDLShowConstantTBTResponse.m
+++ b/SmartDeviceLink/SDLShowConstantTBTResponse.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLShowConstantTBTResponse
 
 - (instancetype)init {
@@ -16,3 +18,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLShowResponse.h b/SmartDeviceLink/SDLShowResponse.h
index 1963390ec..0cb87e942 100644
--- a/SmartDeviceLink/SDLShowResponse.h
+++ b/SmartDeviceLink/SDLShowResponse.h
@@ -9,6 +9,11 @@
  *
  * Since SmartDeviceLink 1.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLShowResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLShowResponse.m b/SmartDeviceLink/SDLShowResponse.m
index 10ce51834..cca46c426 100644
--- a/SmartDeviceLink/SDLShowResponse.m
+++ b/SmartDeviceLink/SDLShowResponse.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLShowResponse
 
 - (instancetype)init {
@@ -16,3 +18,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSingleTireStatus.h b/SmartDeviceLink/SDLSingleTireStatus.h
index e57e04230..da8e71077 100644
--- a/SmartDeviceLink/SDLSingleTireStatus.h
+++ b/SmartDeviceLink/SDLSingleTireStatus.h
@@ -10,11 +10,16 @@
  *
  * @since SmartDeviceLink 2.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLSingleTireStatus : SDLRPCStruct
 
 /**
  * @abstract The volume status of a single tire
  */
-@property (strong) SDLComponentVolumeStatus status;
+@property (strong, nonatomic) SDLComponentVolumeStatus status;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSlider.h b/SmartDeviceLink/SDLSlider.h
index fdf143d2b..31a312bd7 100644
--- a/SmartDeviceLink/SDLSlider.h
+++ b/SmartDeviceLink/SDLSlider.h
@@ -11,34 +11,37 @@
  *
  * Since SmartDeviceLink 2.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLSlider : SDLRPCRequest
 
 - (instancetype)initWithNumTicks:(UInt8)numTicks position:(UInt8)position;
 
-- (instancetype)initWithNumTicks:(UInt8)numTicks position:(UInt8)position sliderHeader:(NSString *)sliderHeader sliderFooter:(NSString *)sliderFooter timeout:(UInt16)timeout;
+- (instancetype)initWithNumTicks:(UInt8)numTicks position:(UInt8)position sliderHeader:(NSString *)sliderHeader sliderFooter:(nullable NSString *)sliderFooter timeout:(UInt16)timeout;
 
-- (instancetype)initWithNumTicks:(UInt8)numTicks position:(UInt8)position sliderHeader:(NSString *)sliderHeader sliderFooters:(NSArray<NSString *> *)sliderFooters timeout:(UInt16)timeout;
+- (instancetype)initWithNumTicks:(UInt8)numTicks position:(UInt8)position sliderHeader:(NSString *)sliderHeader sliderFooters:(nullable NSArray<NSString *> *)sliderFooters timeout:(UInt16)timeout;
 
 /**
  * @abstract Represents a number of selectable items on a horizontal axis
  *
  * Required, Integer, 2 - 26
  */
-@property (strong) NSNumber<SDLInt> *numTicks;
+@property (strong, nonatomic) NSNumber<SDLInt> *numTicks;
 
 /**
  * @abstract An Initial position of slider control
  *
  * Required, Integer, 1 - 26
  */
-@property (strong) NSNumber<SDLInt> *position;
+@property (strong, nonatomic) NSNumber<SDLInt> *position;
 
 /**
  * @abstract A text header to display
  *
  * Rquired, Max length 500 chars
  */
-@property (strong) NSString *sliderHeader;
+@property (strong, nonatomic) NSString *sliderHeader;
 
 /**
  * @abstract A text footer to display
@@ -53,7 +56,7 @@
  *
  * Optional, Array of Strings, Array length 1 - 26, Max string length 500 chars
  */
-@property (strong) NSMutableArray<NSString *> *sliderFooter;
+@property (strong, nonatomic, nullable) NSMutableArray<NSString *> *sliderFooter;
 
 /**
  * @abstract An App defined timeout
@@ -64,6 +67,8 @@
  *
  * Optional, Integer, 1000 - 65535
  */
-@property (strong) NSNumber<SDLInt> *timeout;
+@property (strong, nonatomic, nullable) NSNumber<SDLInt> *timeout;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSlider.m b/SmartDeviceLink/SDLSlider.m
index f9587c774..702ca2531 100644
--- a/SmartDeviceLink/SDLSlider.m
+++ b/SmartDeviceLink/SDLSlider.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLSlider
 
 - (instancetype)init {
@@ -15,7 +17,7 @@
     return self;
 }
 
-- (instancetype)initWithNumTicks:(UInt8)numTicks position:(UInt8)position sliderHeader:(NSString *)sliderHeader sliderFooter:(NSString *)sliderFooter timeout:(UInt16)timeout {
+- (instancetype)initWithNumTicks:(UInt8)numTicks position:(UInt8)position sliderHeader:(NSString *)sliderHeader sliderFooter:(nullable NSString *)sliderFooter timeout:(UInt16)timeout {
     NSMutableArray *sliderFooters = [NSMutableArray arrayWithCapacity:numTicks];
 
     // Populates array with the same footer value for each position
@@ -26,7 +28,7 @@
     return [self initWithNumTicks:numTicks position:position sliderHeader:sliderHeader sliderFooter:[sliderFooters copy] timeout:timeout];
 }
 
-- (instancetype)initWithNumTicks:(UInt8)numTicks position:(UInt8)position sliderHeader:(NSString *)sliderHeader sliderFooters:(NSArray<NSString *> *)sliderFooters timeout:(UInt16)timeout {
+- (instancetype)initWithNumTicks:(UInt8)numTicks position:(UInt8)position sliderHeader:(NSString *)sliderHeader sliderFooters:(nullable NSArray<NSString *> *)sliderFooters timeout:(UInt16)timeout {
     self = [self initWithNumTicks:numTicks position:position];
     if (!self) {
         return nil;
@@ -75,20 +77,22 @@
     return [parameters sdl_objectForName:SDLNameSliderHeader];
 }
 
-- (void)setSliderFooter:(NSMutableArray<NSString *> *)sliderFooter {
+- (void)setSliderFooter:(nullable NSMutableArray<NSString *> *)sliderFooter {
     [parameters sdl_setObject:sliderFooter forName:SDLNameSliderFooter];
 }
 
-- (NSMutableArray<NSString *> *)sliderFooter {
+- (nullable NSMutableArray<NSString *> *)sliderFooter {
     return [parameters sdl_objectForName:SDLNameSliderFooter];
 }
 
-- (void)setTimeout:(NSNumber<SDLInt> *)timeout {
+- (void)setTimeout:(nullable NSNumber<SDLInt> *)timeout {
     [parameters sdl_setObject:timeout forName:SDLNameTimeout];
 }
 
-- (NSNumber<SDLInt> *)timeout {
+- (nullable NSNumber<SDLInt> *)timeout {
     return [parameters sdl_objectForName:SDLNameTimeout];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSliderResponse.h b/SmartDeviceLink/SDLSliderResponse.h
index f31a74a6e..1dd4232b4 100644
--- a/SmartDeviceLink/SDLSliderResponse.h
+++ b/SmartDeviceLink/SDLSliderResponse.h
@@ -9,11 +9,16 @@
  *
  * Since SmartDeviceLink 2.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLSliderResponse : SDLRPCResponse
 
 /**
  * @abstract The selected position of the slider.
  */
-@property (strong) NSNumber<SDLInt> *sliderPosition;
+@property (strong, nonatomic, nullable) NSNumber<SDLInt> *sliderPosition;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSliderResponse.m b/SmartDeviceLink/SDLSliderResponse.m
index 022b6a0a8..2b41bf9e3 100644
--- a/SmartDeviceLink/SDLSliderResponse.m
+++ b/SmartDeviceLink/SDLSliderResponse.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLSliderResponse
 
 - (instancetype)init {
@@ -15,12 +17,14 @@
     return self;
 }
 
-- (void)setSliderPosition:(NSNumber<SDLInt> *)sliderPosition {
+- (void)setSliderPosition:(nullable NSNumber<SDLInt> *)sliderPosition {
     [parameters sdl_setObject:sliderPosition forName:SDLNameSliderPosition];
 }
 
-- (NSNumber<SDLInt> *)sliderPosition {
+- (nullable NSNumber<SDLInt> *)sliderPosition {
     return [parameters objectForKey:SDLNameSliderPosition];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSoftButton.h b/SmartDeviceLink/SDLSoftButton.h
index 83d3e3049..a5cc9d7a4 100644
--- a/SmartDeviceLink/SDLSoftButton.h
+++ b/SmartDeviceLink/SDLSoftButton.h
@@ -10,20 +10,23 @@
 
 @class SDLImage;
 
+NS_ASSUME_NONNULL_BEGIN
 
 @interface SDLSoftButton : SDLRPCStruct <SDLRequestHandler>
 
-- (instancetype)initWithHandler:(SDLRPCNotificationHandler)handler;
+- (instancetype)initWithHandler:(nullable SDLRPCNotificationHandler)handler;
 
-- (instancetype)initWithType:(SDLSoftButtonType)type text:(NSString *)text image:(SDLImage *)image highlighted:(BOOL)highlighted buttonId:(UInt16)buttonId systemAction:(SDLSystemAction)systemAction handler:(SDLRPCNotificationHandler)handler;
+- (instancetype)initWithType:(SDLSoftButtonType)type text:(nullable NSString *)text image:(nullable SDLImage *)image highlighted:(BOOL)highlighted buttonId:(UInt16)buttonId systemAction:(nullable SDLSystemAction)systemAction handler:(nullable SDLRPCNotificationHandler)handler;
 
 @property (copy, nonatomic) SDLRPCNotificationHandler handler;
 
-@property (strong) SDLSoftButtonType type;
-@property (strong) NSString *text;
-@property (strong) SDLImage *image;
-@property (strong) NSNumber<SDLBool> *isHighlighted;
-@property (strong) NSNumber<SDLInt> *softButtonID;
-@property (strong) SDLSystemAction systemAction;
+@property (strong, nonatomic) SDLSoftButtonType type;
+@property (strong, nonatomic, nullable) NSString *text;
+@property (strong, nonatomic, nullable) SDLImage *image;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *isHighlighted;
+@property (strong, nonatomic) NSNumber<SDLInt> *softButtonID;
+@property (strong, nonatomic, nullable) SDLSystemAction systemAction;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSoftButton.m b/SmartDeviceLink/SDLSoftButton.m
index 19dd86193..9f9a5c21e 100644
--- a/SmartDeviceLink/SDLSoftButton.m
+++ b/SmartDeviceLink/SDLSoftButton.m
@@ -7,10 +7,11 @@
 #import "SDLImage.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
 
 @implementation SDLSoftButton
 
-- (instancetype)initWithHandler:(SDLRPCNotificationHandler)handler {
+- (instancetype)initWithHandler:(nullable SDLRPCNotificationHandler)handler {
     self = [self init];
     if (!self) {
         return nil;
@@ -21,7 +22,7 @@
     return self;
 }
 
-- (instancetype)initWithType:(SDLSoftButtonType)type text:(NSString *)text image:(SDLImage *)image highlighted:(BOOL)highlighted buttonId:(UInt16)buttonId systemAction:(SDLSystemAction)systemAction handler:(SDLRPCNotificationHandler)handler {
+- (instancetype)initWithType:(SDLSoftButtonType)type text:(nullable NSString *)text image:(nullable SDLImage *)image highlighted:(BOOL)highlighted buttonId:(UInt16)buttonId systemAction:(nullable SDLSystemAction)systemAction handler:(nullable SDLRPCNotificationHandler)handler {
     self = [self initWithHandler:handler];
     if (!self) {
         return nil;
@@ -46,27 +47,27 @@
     return [store sdl_objectForName:SDLNameType];
 }
 
-- (void)setText:(NSString *)text {
+- (void)setText:(nullable NSString *)text {
     [store sdl_setObject:text forName:SDLNameText];
 }
 
-- (NSString *)text {
+- (nullable NSString *)text {
     return [store sdl_objectForName:SDLNameText];
 }
 
-- (void)setImage:(SDLImage *)image {
+- (void)setImage:(nullable SDLImage *)image {
     [store sdl_setObject:image forName:SDLNameImage];
 }
 
-- (SDLImage *)image {
+- (nullable SDLImage *)image {
     return [store sdl_objectForName:SDLNameImage ofClass:SDLImage.class];
 }
 
-- (void)setIsHighlighted:(NSNumber<SDLBool> *)isHighlighted {
+- (void)setIsHighlighted:(nullable NSNumber<SDLBool> *)isHighlighted {
     [store sdl_setObject:isHighlighted forName:SDLNameIsHighlighted];
 }
 
-- (NSNumber<SDLBool> *)isHighlighted {
+- (nullable NSNumber<SDLBool> *)isHighlighted {
     return [store sdl_objectForName:SDLNameIsHighlighted];
 }
 
@@ -78,12 +79,14 @@
     return [store sdl_objectForName:SDLNameSoftButtonId];
 }
 
-- (void)setSystemAction:(SDLSystemAction)systemAction {
+- (void)setSystemAction:(nullable SDLSystemAction)systemAction {
     [store sdl_setObject:systemAction forName:SDLNameSystemAction];
 }
 
-- (SDLSystemAction)systemAction {
+- (nullable SDLSystemAction)systemAction {
     return [store sdl_objectForName:SDLNameSystemAction];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSoftButtonCapabilities.h b/SmartDeviceLink/SDLSoftButtonCapabilities.h
index 0fb85c301..c06cd026f 100644
--- a/SmartDeviceLink/SDLSoftButtonCapabilities.h
+++ b/SmartDeviceLink/SDLSoftButtonCapabilities.h
@@ -9,6 +9,9 @@
  *
  * @since SDL 2.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLSoftButtonCapabilities : SDLRPCStruct
 
 /**
@@ -18,7 +21,7 @@
  *
  * Required, Boolean
  */
-@property (strong) NSNumber<SDLBool> *shortPressAvailable;
+@property (strong, nonatomic) NSNumber<SDLBool> *shortPressAvailable;
 
 /**
  * @abstract The button supports a LONG press.
@@ -27,7 +30,7 @@
  *
  * Required, Boolean
  */
-@property (strong) NSNumber<SDLBool> *longPressAvailable;
+@property (strong, nonatomic) NSNumber<SDLBool> *longPressAvailable;
 
 /**
  * @abstract The button supports "button down" and "button up".
@@ -36,13 +39,15 @@
  *
  * Required, Boolean
  */
-@property (strong) NSNumber<SDLBool> *upDownAvailable;
+@property (strong, nonatomic) NSNumber<SDLBool> *upDownAvailable;
 
 /**
  * @abstract The button supports referencing a static or dynamic image.
  *
  * Required, Boolean
  */
-@property (strong) NSNumber<SDLBool> *imageSupported;
+@property (strong, nonatomic) NSNumber<SDLBool> *imageSupported;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSoftButtonCapabilities.m b/SmartDeviceLink/SDLSoftButtonCapabilities.m
index 0bad31346..6bf391496 100644
--- a/SmartDeviceLink/SDLSoftButtonCapabilities.m
+++ b/SmartDeviceLink/SDLSoftButtonCapabilities.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLSoftButtonCapabilities
 
 - (void)setShortPressAvailable:(NSNumber<SDLBool> *)shortPressAvailable {
@@ -42,3 +44,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSpeak.h b/SmartDeviceLink/SDLSpeak.h
index e5d66d49e..528c3f133 100644
--- a/SmartDeviceLink/SDLSpeak.h
+++ b/SmartDeviceLink/SDLSpeak.h
@@ -38,6 +38,9 @@
  * @since SmartDeviceLink 1.0
  * @see SDLAlert
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLSpeak : SDLRPCRequest
 
 - (instancetype)initWithTTS:(NSString *)ttsText;
@@ -53,6 +56,8 @@
  * 
  * @see SDLTTSChunk
  */
-@property (strong) NSMutableArray<SDLTTSChunk *> *ttsChunks;
+@property (strong, nonatomic) NSMutableArray<SDLTTSChunk *> *ttsChunks;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSpeak.m b/SmartDeviceLink/SDLSpeak.m
index adae9be72..774947831 100644
--- a/SmartDeviceLink/SDLSpeak.m
+++ b/SmartDeviceLink/SDLSpeak.m
@@ -8,6 +8,8 @@
 #import "SDLNames.h"
 #import "SDLTTSChunk.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLSpeak
 
 - (instancetype)init {
@@ -41,3 +43,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSpeakResponse.h b/SmartDeviceLink/SDLSpeakResponse.h
index c241e7d37..8e4c44261 100644
--- a/SmartDeviceLink/SDLSpeakResponse.h
+++ b/SmartDeviceLink/SDLSpeakResponse.h
@@ -9,6 +9,11 @@
  *
  * Since SmartDeviceLink 1.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLSpeakResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSpeakResponse.m b/SmartDeviceLink/SDLSpeakResponse.m
index db7ec8734..f8e8a248c 100644
--- a/SmartDeviceLink/SDLSpeakResponse.m
+++ b/SmartDeviceLink/SDLSpeakResponse.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLSpeakResponse
 
 - (instancetype)init {
@@ -16,3 +18,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLStartTime.h b/SmartDeviceLink/SDLStartTime.h
index 36f8cdf02..5fbc0e987 100644
--- a/SmartDeviceLink/SDLStartTime.h
+++ b/SmartDeviceLink/SDLStartTime.h
@@ -9,6 +9,9 @@
  *
  * @since SDL 1.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLStartTime : SDLRPCStruct
 
 - (instancetype)initWithHours:(UInt8)hours minutes:(UInt8)minutes seconds:(UInt8)seconds;
@@ -20,20 +23,22 @@
  *
  * Required, Integer, 0 - 59
  */
-@property (strong) NSNumber<SDLInt> *hours;
+@property (strong, nonatomic) NSNumber<SDLInt> *hours;
 
 /**
  * @abstract The minute of the media clock
  *
  * Required, Integer, 0 - 59
  */
-@property (strong) NSNumber<SDLInt> *minutes;
+@property (strong, nonatomic) NSNumber<SDLInt> *minutes;
 
 /**
  * @abstract The second of the media clock
  *
  * Required, Integer, 0 - 59
  */
-@property (strong) NSNumber<SDLInt> *seconds;
+@property (strong, nonatomic) NSNumber<SDLInt> *seconds;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLStartTime.m b/SmartDeviceLink/SDLStartTime.m
index c4c4e09e7..df8490f7a 100644
--- a/SmartDeviceLink/SDLStartTime.m
+++ b/SmartDeviceLink/SDLStartTime.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLStartTime
 
 - (instancetype)initWithHours:(UInt8)hours minutes:(UInt8)minutes seconds:(UInt8)seconds {
@@ -47,3 +49,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLStreamDelegate.h b/SmartDeviceLink/SDLStreamDelegate.h
index fdd8bfbac..f6b0115ad 100644
--- a/SmartDeviceLink/SDLStreamDelegate.h
+++ b/SmartDeviceLink/SDLStreamDelegate.h
@@ -3,6 +3,8 @@
 
 #import <Foundation/Foundation.h>
 
+NS_ASSUME_NONNULL_BEGIN
+
 // Convenience typedefs
 typedef void (^SDLStreamOpenHandler)(NSStream *stream);
 typedef void (^SDLStreamHasBytesHandler)(NSInputStream *istream);
@@ -13,10 +15,12 @@ typedef void (^SDLStreamEndHandler)(NSStream *stream);
 
 @interface SDLStreamDelegate : NSObject <NSStreamDelegate>
 
-@property (nonatomic, copy) SDLStreamOpenHandler streamOpenHandler;
-@property (nonatomic, copy) SDLStreamHasBytesHandler streamHasBytesHandler;
-@property (nonatomic, copy) SDLStreamHasSpaceHandler streamHasSpaceHandler;
-@property (nonatomic, copy) SDLStreamErrorHandler streamErrorHandler;
-@property (nonatomic, copy) SDLStreamEndHandler streamEndHandler;
+@property (nullable, nonatomic, copy) SDLStreamOpenHandler streamOpenHandler;
+@property (nullable, nonatomic, copy) SDLStreamHasBytesHandler streamHasBytesHandler;
+@property (nullable, nonatomic, copy) SDLStreamHasSpaceHandler streamHasSpaceHandler;
+@property (nullable, nonatomic, copy) SDLStreamErrorHandler streamErrorHandler;
+@property (nullable, nonatomic, copy) SDLStreamEndHandler streamEndHandler;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLStreamDelegate.m b/SmartDeviceLink/SDLStreamDelegate.m
index 6c2db6c34..1e60fb3f5 100644
--- a/SmartDeviceLink/SDLStreamDelegate.m
+++ b/SmartDeviceLink/SDLStreamDelegate.m
@@ -5,6 +5,8 @@
 #import "SDLStreamDelegate.h"
 #import "SDLDebugTool.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLStreamDelegate () {
     dispatch_queue_t _input_stream_queue;
 }
@@ -90,3 +92,5 @@ SDLStreamEndHandler defaultStreamEndHandler = ^(NSStream *stream) {
 };
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSubscribeButton.h b/SmartDeviceLink/SDLSubscribeButton.h
index d964ea244..6b3465636 100644
--- a/SmartDeviceLink/SDLSubscribeButton.h
+++ b/SmartDeviceLink/SDLSubscribeButton.h
@@ -58,6 +58,9 @@
  * Since SmartDeviceLink 1.0<br/>
  * See SDLUnsubscribeButton
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLSubscribeButton : SDLRPCRequest <SDLRequestHandler>
 
 /**
@@ -67,9 +70,9 @@
  *
  *  @return An SDLSubscribeButton object
  */
-- (instancetype)initWithHandler:(SDLRPCNotificationHandler)handler;
+- (instancetype)initWithHandler:(nullable SDLRPCNotificationHandler)handler;
 
-- (instancetype)initWithButtonName:(SDLButtonName)buttonName handler:(SDLRPCNotificationHandler)handler;
+- (instancetype)initWithButtonName:(SDLButtonName)buttonName handler:(nullable SDLRPCNotificationHandler)handler;
 
 /**
  *  A handler that will let you know when the button you subscribed to is selected.
@@ -82,6 +85,8 @@
  * @abstract The name of the button to subscribe to
  * @discussion An enum value, see <i>SDLButtonName</i>
  */
-@property (strong) SDLButtonName buttonName;
+@property (strong, nonatomic) SDLButtonName buttonName;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSubscribeButton.m b/SmartDeviceLink/SDLSubscribeButton.m
index b53cec808..50d9ac37b 100644
--- a/SmartDeviceLink/SDLSubscribeButton.m
+++ b/SmartDeviceLink/SDLSubscribeButton.m
@@ -7,6 +7,7 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
 
 @implementation SDLSubscribeButton
 
@@ -16,7 +17,7 @@
     return self;
 }
 
-- (instancetype)initWithHandler:(SDLRPCNotificationHandler)handler {
+- (instancetype)initWithHandler:(nullable SDLRPCNotificationHandler)handler {
     self = [self init];
     if (!self) {
         return nil;
@@ -27,7 +28,7 @@
     return self;
 }
 
-- (instancetype)initWithButtonName:(SDLButtonName)buttonName handler:(SDLRPCNotificationHandler)handler {
+- (instancetype)initWithButtonName:(SDLButtonName)buttonName handler:(nullable SDLRPCNotificationHandler)handler {
     self = [self init];
     if (!self) {
         return nil;
@@ -48,3 +49,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSubscribeButtonResponse.h b/SmartDeviceLink/SDLSubscribeButtonResponse.h
index bf9c22604..74a6fad0b 100644
--- a/SmartDeviceLink/SDLSubscribeButtonResponse.h
+++ b/SmartDeviceLink/SDLSubscribeButtonResponse.h
@@ -9,6 +9,11 @@
  *
  * Since SmartDeviceLink 1.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLSubscribeButtonResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSubscribeButtonResponse.m b/SmartDeviceLink/SDLSubscribeButtonResponse.m
index 8b232386a..bf2b860f6 100644
--- a/SmartDeviceLink/SDLSubscribeButtonResponse.m
+++ b/SmartDeviceLink/SDLSubscribeButtonResponse.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLSubscribeButtonResponse
 
 - (instancetype)init {
@@ -16,3 +18,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSubscribeVehicleData.h b/SmartDeviceLink/SDLSubscribeVehicleData.h
index 38d3aacff..4e0411d43 100644
--- a/SmartDeviceLink/SDLSubscribeVehicleData.h
+++ b/SmartDeviceLink/SDLSubscribeVehicleData.h
@@ -19,6 +19,9 @@
  * Since SmartDeviceLink 2.0<br/>
  * See SDLUnsubscribeVehicleData SDLGetVehicleData
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLSubscribeVehicleData : SDLRPCRequest
 
 - (instancetype)initWithAccelerationPedalPosition:(BOOL)accelerationPedalPosition airbagStatus:(BOOL)airbagStatus beltStatus:(BOOL)beltStatus bodyInformation:(BOOL)bodyInformation clusterModeStatus:(BOOL)clusterModeStatus deviceStatus:(BOOL)deviceStatus driverBraking:(BOOL)driverBraking eCallInfo:(BOOL)eCallInfo emergencyEvent:(BOOL)emergencyEvent engineTorque:(BOOL)engineTorque externalTemperature:(BOOL)externalTemperature fuelLevel:(BOOL)fuelLevel fuelLevelState:(BOOL)fuelLevelState gps:(BOOL)gps headLampStatus:(BOOL)headLampStatus instantFuelConsumption:(BOOL)instantFuelConsumption myKey:(BOOL)myKey odometer:(BOOL)odometer prndl:(BOOL)prndl rpm:(BOOL)rpm speed:(BOOL)speed steeringWheelAngle:(BOOL)steeringWheelAngle tirePressure:(BOOL)tirePressure wiperStatus:(BOOL)wiperStatus;
@@ -26,103 +29,105 @@
 /**
  * @abstract A boolean value. If true, subscribes Gps data
  */
-@property (strong) NSNumber<SDLBool> *gps;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *gps;
 
 /**
  * @abstract A boolean value. If true, subscribes speed data
  */
-@property (strong) NSNumber<SDLBool> *speed;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *speed;
 
 /**
  * @abstract A boolean value. If true, subscribes rpm data
  */
-@property (strong) NSNumber<SDLBool> *rpm;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *rpm;
 
 /**
  * @abstract A boolean value. If true, subscribes FuelLevel data
  */
-@property (strong) NSNumber<SDLBool> *fuelLevel;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *fuelLevel;
 
 /**
  * @abstract A boolean value. If true, subscribes fuelLevel_State data
  */
-@property (strong) NSNumber<SDLBool> *fuelLevel_State;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *fuelLevel_State;
 
 /**
  * @abstract A boolean value. If true, subscribes instantFuelConsumption data
  */
-@property (strong) NSNumber<SDLBool> *instantFuelConsumption;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *instantFuelConsumption;
 
 /**
  * @abstract A boolean value. If true, subscribes externalTemperature data
  */
-@property (strong) NSNumber<SDLBool> *externalTemperature;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *externalTemperature;
 
 /**
  * @abstract A boolean value. If true, subscribes Currently selected gear data
  */
-@property (strong) NSNumber<SDLBool> *prndl;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *prndl;
 
 /**
  * @abstract A boolean value. If true, subscribes tire pressure status data
  */
-@property (strong) NSNumber<SDLBool> *tirePressure;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *tirePressure;
 
 /**
  * @abstract A boolean value. If true, subscribes odometer data
  */
-@property (strong) NSNumber<SDLBool> *odometer;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *odometer;
 
 /**
  * @abstract A boolean value. If true, subscribes belt Status data
  */
-@property (strong) NSNumber<SDLBool> *beltStatus;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *beltStatus;
 
 /**
  * @abstract A boolean value. If true, subscribes body Information data
  */
-@property (strong) NSNumber<SDLBool> *bodyInformation;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *bodyInformation;
 
 /**
  * @abstract A boolean value. If true, subscribes device Status data
  */
-@property (strong) NSNumber<SDLBool> *deviceStatus;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *deviceStatus;
 
 /**
  * @abstract A boolean value. If true, subscribes driver Braking data
  */
-@property (strong) NSNumber<SDLBool> *driverBraking;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *driverBraking;
 
 /**
  * @abstract A boolean value. If true, subscribes wiper Status data
  */
-@property (strong) NSNumber<SDLBool> *wiperStatus;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *wiperStatus;
 
 /**
  * @abstract A boolean value. If true, subscribes Head Lamp Status data
  */
-@property (strong) NSNumber<SDLBool> *headLampStatus;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *headLampStatus;
 
 /**
  * @abstract A boolean value. If true, subscribes Engine Torque data
  */
-@property (strong) NSNumber<SDLBool> *engineTorque;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *engineTorque;
 
 /**
  * @abstract A boolean value. If true, means the accPedalPosition data has been
  * subscribed.
  */
-@property (strong) NSNumber<SDLBool> *accPedalPosition;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *accPedalPosition;
 
 /**
  * @abstract A boolean value. If true, means the steeringWheelAngle data has been
  * subscribed.
  */
-@property (strong) NSNumber<SDLBool> *steeringWheelAngle;
-@property (strong) NSNumber<SDLBool> *eCallInfo;
-@property (strong) NSNumber<SDLBool> *airbagStatus;
-@property (strong) NSNumber<SDLBool> *emergencyEvent;
-@property (strong) NSNumber<SDLBool> *clusterModeStatus;
-@property (strong) NSNumber<SDLBool> *myKey;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *steeringWheelAngle;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *eCallInfo;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *airbagStatus;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *emergencyEvent;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *clusterModeStatus;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *myKey;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSubscribeVehicleData.m b/SmartDeviceLink/SDLSubscribeVehicleData.m
index 9c1e29d60..d8973045e 100644
--- a/SmartDeviceLink/SDLSubscribeVehicleData.m
+++ b/SmartDeviceLink/SDLSubscribeVehicleData.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLSubscribeVehicleData
 
 - (instancetype)init {
@@ -49,196 +51,198 @@
     return self;
 }
 
-- (void)setGps:(NSNumber<SDLBool> *)gps {
+- (void)setGps:(nullable NSNumber<SDLBool> *)gps {
     [parameters sdl_setObject:gps forName:SDLNameGPS];
 }
 
-- (NSNumber<SDLBool> *)gps {
+- (nullable NSNumber<SDLBool> *)gps {
     return [parameters sdl_objectForName:SDLNameGPS];
 }
 
-- (void)setSpeed:(NSNumber<SDLBool> *)speed {
+- (void)setSpeed:(nullable NSNumber<SDLBool> *)speed {
     [parameters sdl_setObject:speed forName:SDLNameSpeed];
 }
 
-- (NSNumber<SDLBool> *)speed {
+- (nullable NSNumber<SDLBool> *)speed {
     return [parameters sdl_objectForName:SDLNameSpeed];
 }
 
-- (void)setRpm:(NSNumber<SDLBool> *)rpm {
+- (void)setRpm:(nullable NSNumber<SDLBool> *)rpm {
     [parameters sdl_setObject:rpm forName:SDLNameRPM];
 }
 
-- (NSNumber<SDLBool> *)rpm {
+- (nullable NSNumber<SDLBool> *)rpm {
     return [parameters sdl_objectForName:SDLNameRPM];
 }
 
-- (void)setFuelLevel:(NSNumber<SDLBool> *)fuelLevel {
+- (void)setFuelLevel:(nullable NSNumber<SDLBool> *)fuelLevel {
     [parameters sdl_setObject:fuelLevel forName:SDLNameFuelLevel];
 }
 
-- (NSNumber<SDLBool> *)fuelLevel {
+- (nullable NSNumber<SDLBool> *)fuelLevel {
     return [parameters sdl_objectForName:SDLNameFuelLevel];
 }
 
-- (void)setFuelLevel_State:(NSNumber<SDLBool> *)fuelLevel_State {
+- (void)setFuelLevel_State:(nullable NSNumber<SDLBool> *)fuelLevel_State {
     [parameters sdl_setObject:fuelLevel_State forName:SDLNameFuelLevelState];
 }
 
-- (NSNumber<SDLBool> *)fuelLevel_State {
+- (nullable NSNumber<SDLBool> *)fuelLevel_State {
     return [parameters sdl_objectForName:SDLNameFuelLevelState];
 }
 
-- (void)setInstantFuelConsumption:(NSNumber<SDLBool> *)instantFuelConsumption {
+- (void)setInstantFuelConsumption:(nullable NSNumber<SDLBool> *)instantFuelConsumption {
     [parameters sdl_setObject:instantFuelConsumption forName:SDLNameInstantFuelConsumption];
 }
 
-- (NSNumber<SDLBool> *)instantFuelConsumption {
+- (nullable NSNumber<SDLBool> *)instantFuelConsumption {
     return [parameters sdl_objectForName:SDLNameInstantFuelConsumption];
 }
 
-- (void)setExternalTemperature:(NSNumber<SDLBool> *)externalTemperature {
+- (void)setExternalTemperature:(nullable NSNumber<SDLBool> *)externalTemperature {
     [parameters sdl_setObject:externalTemperature forName:SDLNameExternalTemperature];
 }
 
-- (NSNumber<SDLBool> *)externalTemperature {
+- (nullable NSNumber<SDLBool> *)externalTemperature {
     return [parameters sdl_objectForName:SDLNameExternalTemperature];
 }
 
-- (void)setPrndl:(NSNumber<SDLBool> *)prndl {
+- (void)setPrndl:(nullable NSNumber<SDLBool> *)prndl {
     [parameters sdl_setObject:prndl forName:SDLNamePRNDL];
 }
 
-- (NSNumber<SDLBool> *)prndl {
+- (nullable NSNumber<SDLBool> *)prndl {
     return [parameters sdl_objectForName:SDLNamePRNDL];
 }
 
-- (void)setTirePressure:(NSNumber<SDLBool> *)tirePressure {
+- (void)setTirePressure:(nullable NSNumber<SDLBool> *)tirePressure {
     [parameters sdl_setObject:tirePressure forName:SDLNameTirePressure];
 }
 
-- (NSNumber<SDLBool> *)tirePressure {
+- (nullable NSNumber<SDLBool> *)tirePressure {
     return [parameters sdl_objectForName:SDLNameTirePressure];
 }
 
-- (void)setOdometer:(NSNumber<SDLBool> *)odometer {
+- (void)setOdometer:(nullable NSNumber<SDLBool> *)odometer {
     [parameters sdl_setObject:odometer forName:SDLNameOdometer];
 }
 
-- (NSNumber<SDLBool> *)odometer {
+- (nullable NSNumber<SDLBool> *)odometer {
     return [parameters sdl_objectForName:SDLNameOdometer];
 }
 
-- (void)setBeltStatus:(NSNumber<SDLBool> *)beltStatus {
+- (void)setBeltStatus:(nullable NSNumber<SDLBool> *)beltStatus {
     [parameters sdl_setObject:beltStatus forName:SDLNameBeltStatus];
 }
 
-- (NSNumber<SDLBool> *)beltStatus {
+- (nullable NSNumber<SDLBool> *)beltStatus {
     return [parameters sdl_objectForName:SDLNameBeltStatus];
 }
 
-- (void)setBodyInformation:(NSNumber<SDLBool> *)bodyInformation {
+- (void)setBodyInformation:(nullable NSNumber<SDLBool> *)bodyInformation {
     [parameters sdl_setObject:bodyInformation forName:SDLNameBodyInformation];
 }
 
-- (NSNumber<SDLBool> *)bodyInformation {
+- (nullable NSNumber<SDLBool> *)bodyInformation {
     return [parameters sdl_objectForName:SDLNameBodyInformation];
 }
 
-- (void)setDeviceStatus:(NSNumber<SDLBool> *)deviceStatus {
+- (void)setDeviceStatus:(nullable NSNumber<SDLBool> *)deviceStatus {
     [parameters sdl_setObject:deviceStatus forName:SDLNameDeviceStatus];
 }
 
-- (NSNumber<SDLBool> *)deviceStatus {
+- (nullable NSNumber<SDLBool> *)deviceStatus {
     return [parameters sdl_objectForName:SDLNameDeviceStatus];
 }
 
-- (void)setDriverBraking:(NSNumber<SDLBool> *)driverBraking {
+- (void)setDriverBraking:(nullable NSNumber<SDLBool> *)driverBraking {
     [parameters sdl_setObject:driverBraking forName:SDLNameDriverBraking];
 }
 
-- (NSNumber<SDLBool> *)driverBraking {
+- (nullable NSNumber<SDLBool> *)driverBraking {
     return [parameters sdl_objectForName:SDLNameDriverBraking];
 }
 
-- (void)setWiperStatus:(NSNumber<SDLBool> *)wiperStatus {
+- (void)setWiperStatus:(nullable NSNumber<SDLBool> *)wiperStatus {
     [parameters sdl_setObject:wiperStatus forName:SDLNameWiperStatus];
 }
 
-- (NSNumber<SDLBool> *)wiperStatus {
+- (nullable NSNumber<SDLBool> *)wiperStatus {
     return [parameters sdl_objectForName:SDLNameWiperStatus];
 }
 
-- (void)setHeadLampStatus:(NSNumber<SDLBool> *)headLampStatus {
+- (void)setHeadLampStatus:(nullable NSNumber<SDLBool> *)headLampStatus {
     [parameters sdl_setObject:headLampStatus forName:SDLNameHeadLampStatus];
 }
 
-- (NSNumber<SDLBool> *)headLampStatus {
+- (nullable NSNumber<SDLBool> *)headLampStatus {
     return [parameters sdl_objectForName:SDLNameHeadLampStatus];
 }
 
-- (void)setEngineTorque:(NSNumber<SDLBool> *)engineTorque {
+- (void)setEngineTorque:(nullable NSNumber<SDLBool> *)engineTorque {
     [parameters sdl_setObject:engineTorque forName:SDLNameEngineTorque];
 }
 
-- (NSNumber<SDLBool> *)engineTorque {
+- (nullable NSNumber<SDLBool> *)engineTorque {
     return [parameters sdl_objectForName:SDLNameEngineTorque];
 }
 
-- (void)setAccPedalPosition:(NSNumber<SDLBool> *)accPedalPosition {
+- (void)setAccPedalPosition:(nullable NSNumber<SDLBool> *)accPedalPosition {
     [parameters sdl_setObject:accPedalPosition forName:SDLNameAccelerationPedalPosition];
 }
 
-- (NSNumber<SDLBool> *)accPedalPosition {
+- (nullable NSNumber<SDLBool> *)accPedalPosition {
     return [parameters sdl_objectForName:SDLNameAccelerationPedalPosition];
 }
 
-- (void)setSteeringWheelAngle:(NSNumber<SDLBool> *)steeringWheelAngle {
+- (void)setSteeringWheelAngle:(nullable NSNumber<SDLBool> *)steeringWheelAngle {
     [parameters sdl_setObject:steeringWheelAngle forName:SDLNameSteeringWheelAngle];
 }
 
-- (NSNumber<SDLBool> *)steeringWheelAngle {
+- (nullable NSNumber<SDLBool> *)steeringWheelAngle {
     return [parameters sdl_objectForName:SDLNameSteeringWheelAngle];
 }
 
-- (void)setECallInfo:(NSNumber<SDLBool> *)eCallInfo {
+- (void)setECallInfo:(nullable NSNumber<SDLBool> *)eCallInfo {
     [parameters sdl_setObject:eCallInfo forName:SDLNameECallInfo];
 }
 
-- (NSNumber<SDLBool> *)eCallInfo {
+- (nullable NSNumber<SDLBool> *)eCallInfo {
     return [parameters sdl_objectForName:SDLNameECallInfo];
 }
 
-- (void)setAirbagStatus:(NSNumber<SDLBool> *)airbagStatus {
+- (void)setAirbagStatus:(nullable NSNumber<SDLBool> *)airbagStatus {
     [parameters sdl_setObject:airbagStatus forName:SDLNameAirbagStatus];
 }
 
-- (NSNumber<SDLBool> *)airbagStatus {
+- (nullable NSNumber<SDLBool> *)airbagStatus {
     return [parameters sdl_objectForName:SDLNameAirbagStatus];
 }
 
-- (void)setEmergencyEvent:(NSNumber<SDLBool> *)emergencyEvent {
+- (void)setEmergencyEvent:(nullable NSNumber<SDLBool> *)emergencyEvent {
     [parameters sdl_setObject:emergencyEvent forName:SDLNameEmergencyEvent];
 }
 
-- (NSNumber<SDLBool> *)emergencyEvent {
+- (nullable NSNumber<SDLBool> *)emergencyEvent {
     return [parameters sdl_objectForName:SDLNameEmergencyEvent];
 }
 
-- (void)setClusterModeStatus:(NSNumber<SDLBool> *)clusterModeStatus {
+- (void)setClusterModeStatus:(nullable NSNumber<SDLBool> *)clusterModeStatus {
     [parameters sdl_setObject:clusterModeStatus forName:SDLNameClusterModeStatus];
 }
 
-- (NSNumber<SDLBool> *)clusterModeStatus {
+- (nullable NSNumber<SDLBool> *)clusterModeStatus {
     return [parameters sdl_objectForName:SDLNameClusterModeStatus];
 }
 
-- (void)setMyKey:(NSNumber<SDLBool> *)myKey {
+- (void)setMyKey:(nullable NSNumber<SDLBool> *)myKey {
     [parameters sdl_setObject:myKey forName:SDLNameMyKey];
 }
 
-- (NSNumber<SDLBool> *)myKey {
+- (nullable NSNumber<SDLBool> *)myKey {
     return [parameters sdl_objectForName:SDLNameMyKey];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSubscribeVehicleDataResponse.h b/SmartDeviceLink/SDLSubscribeVehicleDataResponse.h
index ca7d9917f..b32c0ca7a 100644
--- a/SmartDeviceLink/SDLSubscribeVehicleDataResponse.h
+++ b/SmartDeviceLink/SDLSubscribeVehicleDataResponse.h
@@ -11,106 +11,111 @@
  *
  * Since SmartDeviceLink 2.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLSubscribeVehicleDataResponse : SDLRPCResponse
 
 /**
  * @abstract A SDLVehicleDataResult* value. See GPSData.
  */
-@property (strong) SDLVehicleDataResult *gps;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *gps;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The vehicle speed in kilometers per hour.
  */
-@property (strong) SDLVehicleDataResult *speed;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *speed;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The number of revolutions per minute of the engine.
  */
-@property (strong) SDLVehicleDataResult *rpm;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *rpm;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The fuel level in the tank (percentage)
  */
-@property (strong) SDLVehicleDataResult *fuelLevel;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *fuelLevel;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The fuel level state.
  */
-@property (strong) SDLVehicleDataResult *fuelLevel_State;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *fuelLevel_State;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The instantaneous fuel consumption in microlitres.
  */
-@property (strong) SDLVehicleDataResult *instantFuelConsumption;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *instantFuelConsumption;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The external temperature in degrees celsius.
  */
-@property (strong) SDLVehicleDataResult *externalTemperature;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *externalTemperature;
 
 /**
  * @abstract A SDLVehicleDataResult* value. See PRNDL.
  */
-@property (strong) SDLVehicleDataResult *prndl;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *prndl;
 
 /**
  * @abstract A SDLVehicleDataResult* value. See TireStatus.
  */
-@property (strong) SDLVehicleDataResult *tirePressure;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *tirePressure;
 
 /**
  * @abstract A SDLVehicleDataResult* value. Odometer in km.
  */
-@property (strong) SDLVehicleDataResult *odometer;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *odometer;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The status of the seat belts.
  */
-@property (strong) SDLVehicleDataResult *beltStatus;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *beltStatus;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The body information including power modes.
  */
-@property (strong) SDLVehicleDataResult *bodyInformation;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *bodyInformation;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The device status including signal and battery strength.
  */
-@property (strong) SDLVehicleDataResult *deviceStatus;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *deviceStatus;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The status of the brake pedal.
  */
-@property (strong) SDLVehicleDataResult *driverBraking;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *driverBraking;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The status of the wipers.
  */
-@property (strong) SDLVehicleDataResult *wiperStatus;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *wiperStatus;
 
 /**
  * @abstract A SDLVehicleDataResult* value. Status of the head lamps.
  */
-@property (strong) SDLVehicleDataResult *headLampStatus;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *headLampStatus;
 
 /**
  * @abstract A SDLVehicleDataResult* value. Torque value for engine (in Nm) on non-diesel variants.
  */
-@property (strong) SDLVehicleDataResult *engineTorque;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *engineTorque;
 
 /**
  * @abstract A SDLVehicleDataResult* value. Accelerator pedal position (percentage depressed)
  */
-@property (strong) SDLVehicleDataResult *accPedalPosition;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *accPedalPosition;
 
 /**
  * @abstract A SDLVehicleDataResult* value. Current angle of the steering wheel (in deg)
  */
-@property (strong) SDLVehicleDataResult *steeringWheelAngle;
-@property (strong) SDLVehicleDataResult *eCallInfo;
-@property (strong) SDLVehicleDataResult *airbagStatus;
-@property (strong) SDLVehicleDataResult *emergencyEvent;
-@property (strong) SDLVehicleDataResult *clusterModes;
-@property (strong) SDLVehicleDataResult *myKey;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *steeringWheelAngle;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *eCallInfo;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *airbagStatus;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *emergencyEvent;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *clusterModes;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *myKey;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSubscribeVehicleDataResponse.m b/SmartDeviceLink/SDLSubscribeVehicleDataResponse.m
index 75b71bc19..283002a3d 100644
--- a/SmartDeviceLink/SDLSubscribeVehicleDataResponse.m
+++ b/SmartDeviceLink/SDLSubscribeVehicleDataResponse.m
@@ -8,6 +8,8 @@
 #import "SDLNames.h"
 #import "SDLVehicleDataResult.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLSubscribeVehicleDataResponse
 
 - (instancetype)init {
@@ -16,196 +18,198 @@
     return self;
 }
 
-- (void)setGps:(SDLVehicleDataResult *)gps {
+- (void)setGps:(nullable SDLVehicleDataResult *)gps {
     [parameters sdl_setObject:gps forName:SDLNameGPS];
 }
 
-- (SDLVehicleDataResult *)gps {
+- (nullable SDLVehicleDataResult *)gps {
     return [parameters sdl_objectForName:SDLNameGPS ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setSpeed:(SDLVehicleDataResult *)speed {
+- (void)setSpeed:(nullable SDLVehicleDataResult *)speed {
     [parameters sdl_setObject:speed forName:SDLNameSpeed];
 }
 
-- (SDLVehicleDataResult *)speed {
+- (nullable SDLVehicleDataResult *)speed {
     return [parameters sdl_objectForName:SDLNameSpeed ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setRpm:(SDLVehicleDataResult *)rpm {
+- (void)setRpm:(nullable SDLVehicleDataResult *)rpm {
     [parameters sdl_setObject:rpm forName:SDLNameRPM];
 }
 
-- (SDLVehicleDataResult *)rpm {
+- (nullable SDLVehicleDataResult *)rpm {
     return [parameters sdl_objectForName:SDLNameRPM ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setFuelLevel:(SDLVehicleDataResult *)fuelLevel {
+- (void)setFuelLevel:(nullable SDLVehicleDataResult *)fuelLevel {
     [parameters sdl_setObject:fuelLevel forName:SDLNameFuelLevel];
 }
 
-- (SDLVehicleDataResult *)fuelLevel {
+- (nullable SDLVehicleDataResult *)fuelLevel {
     return [parameters sdl_objectForName:SDLNameFuelLevel ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setFuelLevel_State:(SDLVehicleDataResult *)fuelLevel_State {
+- (void)setFuelLevel_State:(nullable SDLVehicleDataResult *)fuelLevel_State {
     [parameters sdl_setObject:fuelLevel_State forName:SDLNameFuelLevelState];
 }
 
-- (SDLVehicleDataResult *)fuelLevel_State {
+- (nullable SDLVehicleDataResult *)fuelLevel_State {
     return [parameters sdl_objectForName:SDLNameFuelLevelState ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setInstantFuelConsumption:(SDLVehicleDataResult *)instantFuelConsumption {
+- (void)setInstantFuelConsumption:(nullable SDLVehicleDataResult *)instantFuelConsumption {
     [parameters sdl_setObject:instantFuelConsumption forName:SDLNameInstantFuelConsumption];
 }
 
-- (SDLVehicleDataResult *)instantFuelConsumption {
+- (nullable SDLVehicleDataResult *)instantFuelConsumption {
     return [parameters sdl_objectForName:SDLNameInstantFuelConsumption ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setExternalTemperature:(SDLVehicleDataResult *)externalTemperature {
+- (void)setExternalTemperature:(nullable SDLVehicleDataResult *)externalTemperature {
     [parameters sdl_setObject:externalTemperature forName:SDLNameExternalTemperature];
 }
 
-- (SDLVehicleDataResult *)externalTemperature {
+- (nullable SDLVehicleDataResult *)externalTemperature {
     return [parameters sdl_objectForName:SDLNameExternalTemperature ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setPrndl:(SDLVehicleDataResult *)prndl {
+- (void)setPrndl:(nullable SDLVehicleDataResult *)prndl {
     [parameters sdl_setObject:prndl forName:SDLNamePRNDL];
 }
 
-- (SDLVehicleDataResult *)prndl {
+- (nullable SDLVehicleDataResult *)prndl {
     return [parameters sdl_objectForName:SDLNamePRNDL ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setTirePressure:(SDLVehicleDataResult *)tirePressure {
+- (void)setTirePressure:(nullable SDLVehicleDataResult *)tirePressure {
     [parameters sdl_setObject:tirePressure forName:SDLNameTirePressure];
 }
 
-- (SDLVehicleDataResult *)tirePressure {
+- (nullable SDLVehicleDataResult *)tirePressure {
     return [parameters sdl_objectForName:SDLNameTirePressure ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setOdometer:(SDLVehicleDataResult *)odometer {
+- (void)setOdometer:(nullable SDLVehicleDataResult *)odometer {
     [parameters sdl_setObject:odometer forName:SDLNameOdometer];
 }
 
-- (SDLVehicleDataResult *)odometer {
+- (nullable SDLVehicleDataResult *)odometer {
     return [parameters sdl_objectForName:SDLNameOdometer ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setBeltStatus:(SDLVehicleDataResult *)beltStatus {
+- (void)setBeltStatus:(nullable SDLVehicleDataResult *)beltStatus {
     [parameters sdl_setObject:beltStatus forName:SDLNameBeltStatus];
 }
 
-- (SDLVehicleDataResult *)beltStatus {
+- (nullable SDLVehicleDataResult *)beltStatus {
     return [parameters sdl_objectForName:SDLNameBeltStatus ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setBodyInformation:(SDLVehicleDataResult *)bodyInformation {
+- (void)setBodyInformation:(nullable SDLVehicleDataResult *)bodyInformation {
     [parameters sdl_setObject:bodyInformation forName:SDLNameBodyInformation];
 }
 
-- (SDLVehicleDataResult *)bodyInformation {
+- (nullable SDLVehicleDataResult *)bodyInformation {
     return [parameters sdl_objectForName:SDLNameBodyInformation ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setDeviceStatus:(SDLVehicleDataResult *)deviceStatus {
+- (void)setDeviceStatus:(nullable SDLVehicleDataResult *)deviceStatus {
     [parameters sdl_setObject:deviceStatus forName:SDLNameDeviceStatus];
 }
 
-- (SDLVehicleDataResult *)deviceStatus {
+- (nullable SDLVehicleDataResult *)deviceStatus {
     return [parameters sdl_objectForName:SDLNameDeviceStatus ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setDriverBraking:(SDLVehicleDataResult *)driverBraking {
+- (void)setDriverBraking:(nullable SDLVehicleDataResult *)driverBraking {
     [parameters sdl_setObject:driverBraking forName:SDLNameDriverBraking];
 }
 
-- (SDLVehicleDataResult *)driverBraking {
+- (nullable SDLVehicleDataResult *)driverBraking {
     return [parameters sdl_objectForName:SDLNameDriverBraking ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setWiperStatus:(SDLVehicleDataResult *)wiperStatus {
+- (void)setWiperStatus:(nullable SDLVehicleDataResult *)wiperStatus {
     [parameters sdl_setObject:wiperStatus forName:SDLNameWiperStatus];
 }
 
-- (SDLVehicleDataResult *)wiperStatus {
+- (nullable SDLVehicleDataResult *)wiperStatus {
     return [parameters sdl_objectForName:SDLNameWiperStatus ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setHeadLampStatus:(SDLVehicleDataResult *)headLampStatus {
+- (void)setHeadLampStatus:(nullable SDLVehicleDataResult *)headLampStatus {
     [parameters sdl_setObject:headLampStatus forName:SDLNameHeadLampStatus];
 }
 
-- (SDLVehicleDataResult *)headLampStatus {
+- (nullable SDLVehicleDataResult *)headLampStatus {
     return [parameters sdl_objectForName:SDLNameHeadLampStatus ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setEngineTorque:(SDLVehicleDataResult *)engineTorque {
+- (void)setEngineTorque:(nullable SDLVehicleDataResult *)engineTorque {
     [parameters sdl_setObject:engineTorque forName:SDLNameEngineTorque];
 }
 
-- (SDLVehicleDataResult *)engineTorque {
+- (nullable SDLVehicleDataResult *)engineTorque {
     return [parameters sdl_objectForName:SDLNameEngineTorque ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setAccPedalPosition:(SDLVehicleDataResult *)accPedalPosition {
+- (void)setAccPedalPosition:(nullable SDLVehicleDataResult *)accPedalPosition {
     [parameters sdl_setObject:accPedalPosition forName:SDLNameAccelerationPedalPosition];
 }
 
-- (SDLVehicleDataResult *)accPedalPosition {
+- (nullable SDLVehicleDataResult *)accPedalPosition {
     return [parameters sdl_objectForName:SDLNameAccelerationPedalPosition ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setSteeringWheelAngle:(SDLVehicleDataResult *)steeringWheelAngle {
+- (void)setSteeringWheelAngle:(nullable SDLVehicleDataResult *)steeringWheelAngle {
     [parameters sdl_setObject:steeringWheelAngle forName:SDLNameSteeringWheelAngle];
 }
 
-- (SDLVehicleDataResult *)steeringWheelAngle {
+- (nullable SDLVehicleDataResult *)steeringWheelAngle {
     return [parameters sdl_objectForName:SDLNameSteeringWheelAngle ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setECallInfo:(SDLVehicleDataResult *)eCallInfo {
+- (void)setECallInfo:(nullable SDLVehicleDataResult *)eCallInfo {
     [parameters sdl_setObject:eCallInfo forName:SDLNameECallInfo];
 }
 
-- (SDLVehicleDataResult *)eCallInfo {
+- (nullable SDLVehicleDataResult *)eCallInfo {
     return [parameters sdl_objectForName:SDLNameECallInfo ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setAirbagStatus:(SDLVehicleDataResult *)airbagStatus {
+- (void)setAirbagStatus:(nullable SDLVehicleDataResult *)airbagStatus {
     [parameters sdl_setObject:airbagStatus forName:SDLNameAirbagStatus];
 }
 
-- (SDLVehicleDataResult *)airbagStatus {
+- (nullable SDLVehicleDataResult *)airbagStatus {
     return [parameters sdl_objectForName:SDLNameAirbagStatus ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setEmergencyEvent:(SDLVehicleDataResult *)emergencyEvent {
+- (void)setEmergencyEvent:(nullable SDLVehicleDataResult *)emergencyEvent {
     [parameters sdl_setObject:emergencyEvent forName:SDLNameEmergencyEvent];
 }
 
-- (SDLVehicleDataResult *)emergencyEvent {
+- (nullable SDLVehicleDataResult *)emergencyEvent {
     return [parameters sdl_objectForName:SDLNameEmergencyEvent ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setClusterModes:(SDLVehicleDataResult *)clusterModes {
+- (void)setClusterModes:(nullable SDLVehicleDataResult *)clusterModes {
     [parameters sdl_setObject:clusterModes forName:SDLNameClusterModes];
 }
 
-- (SDLVehicleDataResult *)clusterModes {
+- (nullable SDLVehicleDataResult *)clusterModes {
     return [parameters sdl_objectForName:SDLNameClusterModes ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setMyKey:(SDLVehicleDataResult *)myKey {
+- (void)setMyKey:(nullable SDLVehicleDataResult *)myKey {
     [parameters sdl_setObject:myKey forName:SDLNameMyKey];
 }
 
-- (SDLVehicleDataResult *)myKey {
+- (nullable SDLVehicleDataResult *)myKey {
     return [parameters sdl_objectForName:SDLNameMyKey ofClass:SDLVehicleDataResult.class];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSubscribeWaypoints.h b/SmartDeviceLink/SDLSubscribeWaypoints.h
index fb04caf97..fc5860f25 100644
--- a/SmartDeviceLink/SDLSubscribeWaypoints.h
+++ b/SmartDeviceLink/SDLSubscribeWaypoints.h
@@ -10,10 +10,19 @@
  * @see SDLUnsubscribeWaypoints
  *
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLSubscribeWayPoints : SDLRPCRequest
 
 @end
 
+NS_ASSUME_NONNULL_END
+
+NS_ASSUME_NONNULL_BEGIN
+
 __deprecated_msg("Use SDLSubscribeWayPoints instead")
-    @interface SDLSubscribeWaypoints : SDLSubscribeWayPoints
-                                       @end
+@interface SDLSubscribeWaypoints : SDLSubscribeWayPoints
+@end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSubscribeWaypoints.m b/SmartDeviceLink/SDLSubscribeWaypoints.m
index 1724ab3a4..65c13be5a 100644
--- a/SmartDeviceLink/SDLSubscribeWaypoints.m
+++ b/SmartDeviceLink/SDLSubscribeWaypoints.m
@@ -6,6 +6,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLSubscribeWayPoints
 
 - (instancetype)init {
@@ -16,6 +18,12 @@
 
 @end
 
+NS_ASSUME_NONNULL_END
+
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLSubscribeWaypoints
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSubscribeWaypointsResponse.h b/SmartDeviceLink/SDLSubscribeWaypointsResponse.h
index cd13c2af6..e70700974 100644
--- a/SmartDeviceLink/SDLSubscribeWaypointsResponse.h
+++ b/SmartDeviceLink/SDLSubscribeWaypointsResponse.h
@@ -3,10 +3,14 @@
 
 #import "SDLRPCResponse.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLSubscribeWayPointsResponse : SDLRPCResponse
 
 @end
 
 __deprecated_msg("Use SDLSubscribeWayPointsResponse instead")
-    @interface SDLSubscribeWaypointsResponse : SDLSubscribeWayPointsResponse
-                                               @end
+@interface SDLSubscribeWaypointsResponse : SDLSubscribeWayPointsResponse
+@end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSyncMsgVersion.h b/SmartDeviceLink/SDLSyncMsgVersion.h
index 873a56f53..7f94afdbf 100644
--- a/SmartDeviceLink/SDLSyncMsgVersion.h
+++ b/SmartDeviceLink/SDLSyncMsgVersion.h
@@ -9,6 +9,9 @@
  * 
  * @since SDL 1.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLSyncMsgVersion : SDLRPCStruct
 
 // TODO: (Alex M.)[2016-12-1] Change from NSInteger to UInt8
@@ -19,12 +22,14 @@
  * 
  * Required, Integer, 1 - 10
  */
-@property (strong) NSNumber<SDLInt> *majorVersion;
+@property (strong, nonatomic) NSNumber<SDLInt> *majorVersion;
 /**
  * @abstract The minor version indicates a change to a previous version that should still allow to be run on an older version (with limited functionality)
  * 
  * Required, Integer, 0 - 1000
  */
-@property (strong) NSNumber<SDLInt> *minorVersion;
+@property (strong, nonatomic) NSNumber<SDLInt> *minorVersion;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSyncMsgVersion.m b/SmartDeviceLink/SDLSyncMsgVersion.m
index f9fbe5206..a7950ce3d 100644
--- a/SmartDeviceLink/SDLSyncMsgVersion.m
+++ b/SmartDeviceLink/SDLSyncMsgVersion.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLSyncMsgVersion
 
 - (instancetype)initWithMajorVersion:(NSInteger)majorVersion minorVersion:(NSInteger)minorVersion {
@@ -41,3 +43,5 @@
     return [NSString stringWithFormat:@"%@.%@", self.majorVersion, self.minorVersion];
 }
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSyncPData.h b/SmartDeviceLink/SDLSyncPData.h
index 33b1b9ab9..8db515479 100644
--- a/SmartDeviceLink/SDLSyncPData.h
+++ b/SmartDeviceLink/SDLSyncPData.h
@@ -4,6 +4,10 @@
 
 #import "SDLRPCRequest.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLSyncPData : SDLRPCRequest
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSyncPData.m b/SmartDeviceLink/SDLSyncPData.m
index 174f020f6..0dceaf65d 100644
--- a/SmartDeviceLink/SDLSyncPData.m
+++ b/SmartDeviceLink/SDLSyncPData.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLSyncPData
 
 - (instancetype)init {
@@ -16,3 +18,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSyncPDataResponse.h b/SmartDeviceLink/SDLSyncPDataResponse.h
index be1905ba1..ae3034a46 100644
--- a/SmartDeviceLink/SDLSyncPDataResponse.h
+++ b/SmartDeviceLink/SDLSyncPDataResponse.h
@@ -4,6 +4,10 @@
 
 #import "SDLRPCResponse.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLSyncPDataResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSyncPDataResponse.m b/SmartDeviceLink/SDLSyncPDataResponse.m
index f2c250c09..2cb1c1164 100644
--- a/SmartDeviceLink/SDLSyncPDataResponse.m
+++ b/SmartDeviceLink/SDLSyncPDataResponse.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLSyncPDataResponse
 
 - (instancetype)init {
@@ -16,3 +18,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSystemRequest.h b/SmartDeviceLink/SDLSystemRequest.h
index a2ec6b4c0..a39b1f712 100644
--- a/SmartDeviceLink/SDLSystemRequest.h
+++ b/SmartDeviceLink/SDLSystemRequest.h
@@ -10,11 +10,16 @@
  * @since SmartDeviceLink 3.0
  *
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLSystemRequest : SDLRPCRequest
 
-- (instancetype)initWithType:(SDLRequestType)requestType fileName:(NSString *)fileName;
+- (instancetype)initWithType:(SDLRequestType)requestType fileName:(nullable NSString *)fileName;
 
-@property (strong) SDLRequestType requestType;
-@property (strong) NSString *fileName;
+@property (strong, nonatomic) SDLRequestType requestType;
+@property (strong, nonatomic, nullable) NSString *fileName;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSystemRequest.m b/SmartDeviceLink/SDLSystemRequest.m
index 553cdad2b..5cb66258d 100644
--- a/SmartDeviceLink/SDLSystemRequest.m
+++ b/SmartDeviceLink/SDLSystemRequest.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLSystemRequest
 
 - (instancetype)init {
@@ -15,7 +17,7 @@
     return self;
 }
 
-- (instancetype)initWithType:(SDLRequestType)requestType fileName:(NSString *)fileName {
+- (instancetype)initWithType:(SDLRequestType)requestType fileName:(nullable NSString *)fileName {
     self = [self init];
     if (!self) {
         return nil;
@@ -35,12 +37,14 @@
     return [parameters sdl_objectForName:SDLNameRequestType];
 }
 
-- (void)setFileName:(NSString *)fileName {
+- (void)setFileName:(nullable NSString *)fileName {
     [parameters sdl_setObject:fileName forName:SDLNameFilename];
 }
 
-- (NSString *)fileName {
+- (nullable NSString *)fileName {
     return [parameters sdl_objectForName:SDLNameFilename];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSystemRequestResponse.h b/SmartDeviceLink/SDLSystemRequestResponse.h
index 805962d3c..306ad48ea 100644
--- a/SmartDeviceLink/SDLSystemRequestResponse.h
+++ b/SmartDeviceLink/SDLSystemRequestResponse.h
@@ -7,6 +7,11 @@
 /** SDLSystemRequestResponse is sent, when SDLSystemRequest has been called.
  * Since<b>SmartDeviceLink 3.0</b>
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLSystemRequestResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLSystemRequestResponse.m b/SmartDeviceLink/SDLSystemRequestResponse.m
index 751e5788f..f202c544d 100644
--- a/SmartDeviceLink/SDLSystemRequestResponse.m
+++ b/SmartDeviceLink/SDLSystemRequestResponse.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLSystemRequestResponse
 
 - (instancetype)init {
@@ -16,3 +18,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLTCPTransport.h b/SmartDeviceLink/SDLTCPTransport.h
index 2c9f55805..ed8da7e41 100644
--- a/SmartDeviceLink/SDLTCPTransport.h
+++ b/SmartDeviceLink/SDLTCPTransport.h
@@ -3,11 +3,15 @@
 
 #import "SDLAbstractTransport.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLTCPTransport : SDLAbstractTransport {
-    CFSocketRef socket;
+    _Nullable CFSocketRef socket;
 }
 
-@property (strong, atomic) NSString *hostName;
-@property (strong, atomic) NSString *portNumber;
+@property (strong, nonatomic) NSString *hostName;
+@property (strong, nonatomic) NSString *portNumber;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLTCPTransport.m b/SmartDeviceLink/SDLTCPTransport.m
index cf46578cb..e1f59aae7 100644
--- a/SmartDeviceLink/SDLTCPTransport.m
+++ b/SmartDeviceLink/SDLTCPTransport.m
@@ -15,13 +15,13 @@
 #import <sys/wait.h>
 #import <unistd.h>
 
+NS_ASSUME_NONNULL_BEGIN
 
 // C function forward declarations.
 int call_socket(const char *hostname, const char *port);
 static void TCPCallback(CFSocketRef socket, CFSocketCallBackType type, CFDataRef address, const void *data, void *info);
 
 @interface SDLTCPTransport () {
-    BOOL _alreadyDestructed;
     dispatch_queue_t _sendQueue;
 }
 
@@ -32,7 +32,6 @@ static void TCPCallback(CFSocketRef socket, CFSocketCallBackType type, CFDataRef
 
 - (instancetype)init {
     if (self = [super init]) {
-        _alreadyDestructed = NO;
         _sendQueue = dispatch_queue_create("com.sdl.transport.tcp.transmit", DISPATCH_QUEUE_SERIAL);
         [SDLDebugTool logInfo:@"SDLTCPTransport Init"
                      withType:SDLDebugType_Transport_iAP
@@ -43,6 +42,9 @@ static void TCPCallback(CFSocketRef socket, CFSocketCallBackType type, CFDataRef
     return self;
 }
 
+- (void)dealloc {
+    [self disconnect];
+}
 
 - (void)connect {
     [SDLDebugTool logInfo:@"TCP Transport attempt connect" withType:SDLDebugType_Transport_TCP];
@@ -87,30 +89,16 @@ static void TCPCallback(CFSocketRef socket, CFSocketCallBackType type, CFDataRef
     });
 }
 
-- (void)destructObjects {
+- (void)disconnect {
     [SDLDebugTool logInfo:@"SDLTCPTransport invalidate and dispose"];
-
-    if (!_alreadyDestructed) {
-        _alreadyDestructed = YES;
-        if (socket != nil) {
-            CFSocketInvalidate(socket);
-            CFRelease(socket);
-        }
+    
+    if (socket != nil) {
+        CFSocketInvalidate(socket);
+        CFRelease(socket);
+        socket = nil;
     }
 }
 
-- (void)disconnect {
-    [self dispose];
-}
-
-- (void)dispose {
-    [self destructObjects];
-}
-
-- (void)dealloc {
-    [self destructObjects];
-}
-
 @end
 
 // C functions
@@ -179,3 +167,5 @@ static void TCPCallback(CFSocketRef socket, CFSocketCallBackType type, CFDataRef
         [SDLDebugTool logInfo:logMessage withType:SDLDebugType_Transport_TCP toOutput:SDLDebugOutput_DeviceConsole];
     }
 }
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLTTSChunk.h b/SmartDeviceLink/SDLTTSChunk.h
index 1adf5e083..ad7690ef0 100644
--- a/SmartDeviceLink/SDLTTSChunk.h
+++ b/SmartDeviceLink/SDLTTSChunk.h
@@ -36,6 +36,9 @@
  *
  *  @since SmartDeviceLink 1.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLTTSChunk : SDLRPCStruct
 
 - (instancetype)initWithText:(NSString *)text type:(SDLSpeechCapabilities)type;
@@ -56,13 +59,15 @@
  *
  * Required, Max length 500
  */
-@property (strong) NSString *text;
+@property (strong, nonatomic) NSString *text;
 
 /**
  * @abstract The type of information in the "text" field (e.g. phrase to be spoken, phoneme specification, name of pre-recorded sound).
  *
  * Required
  */
-@property (strong) SDLSpeechCapabilities type;
+@property (strong, nonatomic) SDLSpeechCapabilities type;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLTTSChunk.m b/SmartDeviceLink/SDLTTSChunk.m
index 8c56757e4..6be3153fb 100644
--- a/SmartDeviceLink/SDLTTSChunk.m
+++ b/SmartDeviceLink/SDLTTSChunk.m
@@ -6,6 +6,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLTTSChunk
 
 - (instancetype)initWithText:(NSString *)text type:(SDLSpeechCapabilities)type {
@@ -40,7 +42,7 @@
     return [self sdl_chunksFromString:nil type:SDLSpeechCapabilitiesSilence];
 }
 
-+ (NSMutableArray<SDLTTSChunk *> *)sdl_chunksFromString:(NSString *)string type:(SDLSpeechCapabilities)type {
++ (nullable NSMutableArray<SDLTTSChunk *> *)sdl_chunksFromString:(nullable NSString *)string type:(SDLSpeechCapabilities)type {
     if (string.length == 0) {
         return nil;
     }
@@ -65,3 +67,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLTextField.h b/SmartDeviceLink/SDLTextField.h
index b4ba0ea4f..2546b2cf1 100644
--- a/SmartDeviceLink/SDLTextField.h
+++ b/SmartDeviceLink/SDLTextField.h
@@ -56,6 +56,9 @@
  *
  * @since SDL 1.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLTextField : SDLRPCStruct
 
 /**
@@ -65,7 +68,7 @@
  *
  * Required
  */
-@property (strong) SDLTextFieldName name;
+@property (strong, nonatomic) SDLTextFieldName name;
 
 /**
  * @abstract The character set that is supported in this field.
@@ -74,20 +77,22 @@
  *
  * Required
  */
-@property (strong) SDLCharacterSet characterSet;
+@property (strong, nonatomic) SDLCharacterSet characterSet;
 
 /**
  * @abstract The number of characters in one row of this field.
  * 
  * Required, Integer 1 - 500
  */
-@property (strong) NSNumber<SDLInt> *width;
+@property (strong, nonatomic) NSNumber<SDLInt> *width;
 
 /**
  * @abstract The number of rows for this text field.
  * 
  * Required, Integer 1 - 8
  */
-@property (strong) NSNumber<SDLInt> *rows;
+@property (strong, nonatomic) NSNumber<SDLInt> *rows;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLTextField.m b/SmartDeviceLink/SDLTextField.m
index 03d7a9015..7e6293f58 100644
--- a/SmartDeviceLink/SDLTextField.m
+++ b/SmartDeviceLink/SDLTextField.m
@@ -8,6 +8,7 @@
 #import "SDLNames.h"
 #import "SDLTextFieldName.h"
 
+NS_ASSUME_NONNULL_BEGIN
 
 @implementation SDLTextField
 
@@ -44,3 +45,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLTimer.h b/SmartDeviceLink/SDLTimer.h
index f9f7be3d9..0382b7f67 100644
--- a/SmartDeviceLink/SDLTimer.h
+++ b/SmartDeviceLink/SDLTimer.h
@@ -4,11 +4,13 @@
 
 #import <Foundation/Foundation.h>
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLTimer : NSObject
 
-@property (nonatomic, copy) void (^elapsedBlock)(void);
-@property (nonatomic, copy) void (^canceledBlock)(void);
-@property (assign) float duration;
+@property (copy, nonatomic, nullable) void (^elapsedBlock)(void);
+@property (copy, nonatomic, nullable) void (^canceledBlock)(void);
+@property (assign, nonatomic) float duration;
 
 - (instancetype)init;
 - (instancetype)initWithDuration:(float)duration __deprecated;
@@ -17,3 +19,5 @@
 - (void)cancel;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLTimer.m b/SmartDeviceLink/SDLTimer.m
index 84ee6e24b..f689ce0c7 100644
--- a/SmartDeviceLink/SDLTimer.m
+++ b/SmartDeviceLink/SDLTimer.m
@@ -4,12 +4,13 @@
 
 #import "SDLTimer.h"
 
+NS_ASSUME_NONNULL_BEGIN
 
 @interface SDLTimer ()
 
-@property (strong) NSTimer *timer;
-@property (assign) BOOL timerRunning;
-@property (nonatomic) BOOL repeat;
+@property (strong, nonatomic, nullable) NSTimer *timer;
+@property (assign, nonatomic) BOOL timerRunning;
+@property (assign, nonatomic) BOOL repeat;
 @end
 
 
@@ -37,6 +38,10 @@
     return self;
 }
 
+- (void)dealloc {
+    [self cancel];
+}
+
 - (void)start {
     if (self.duration > 0) {
         [self stopAndDestroyTimer];
@@ -72,8 +77,6 @@
     }
 }
 
-- (void)dealloc {
-    [self cancel];
-}
-
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLTireStatus.h b/SmartDeviceLink/SDLTireStatus.h
index c65850303..51e3a9db0 100644
--- a/SmartDeviceLink/SDLTireStatus.h
+++ b/SmartDeviceLink/SDLTireStatus.h
@@ -3,17 +3,22 @@
 
 #import "SDLRPCMessage.h"
 
-@class SDLSingleTireStatus;
 #import "SDLWarningLightStatus.h"
 
+@class SDLSingleTireStatus;
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLTireStatus : SDLRPCStruct
 
-@property (strong) SDLWarningLightStatus pressureTelltale;
-@property (strong) SDLSingleTireStatus *leftFront;
-@property (strong) SDLSingleTireStatus *rightFront;
-@property (strong) SDLSingleTireStatus *leftRear;
-@property (strong) SDLSingleTireStatus *rightRear;
-@property (strong) SDLSingleTireStatus *innerLeftRear;
-@property (strong) SDLSingleTireStatus *innerRightRear;
+@property (strong, nonatomic) SDLWarningLightStatus pressureTelltale;
+@property (strong, nonatomic) SDLSingleTireStatus *leftFront;
+@property (strong, nonatomic) SDLSingleTireStatus *rightFront;
+@property (strong, nonatomic) SDLSingleTireStatus *leftRear;
+@property (strong, nonatomic) SDLSingleTireStatus *rightRear;
+@property (strong, nonatomic) SDLSingleTireStatus *innerLeftRear;
+@property (strong, nonatomic) SDLSingleTireStatus *innerRightRear;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLTireStatus.m b/SmartDeviceLink/SDLTireStatus.m
index 9020fd584..aad17cdde 100644
--- a/SmartDeviceLink/SDLTireStatus.m
+++ b/SmartDeviceLink/SDLTireStatus.m
@@ -6,7 +6,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 #import "SDLSingleTireStatus.h"
-#import "SDLWarningLightStatus.h"
+
+NS_ASSUME_NONNULL_BEGIN
 
 @implementation SDLTireStatus
 
@@ -67,3 +68,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLTouchCoord.h b/SmartDeviceLink/SDLTouchCoord.h
index 8e719e3a8..156511585 100644
--- a/SmartDeviceLink/SDLTouchCoord.h
+++ b/SmartDeviceLink/SDLTouchCoord.h
@@ -4,9 +4,13 @@
 
 #import "SDLRPCMessage.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLTouchCoord : SDLRPCStruct
 
-@property (strong) NSNumber<SDLFloat> *x;
-@property (strong) NSNumber<SDLFloat> *y;
+@property (strong, nonatomic) NSNumber<SDLFloat> *x;
+@property (strong, nonatomic) NSNumber<SDLFloat> *y;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLTouchCoord.m b/SmartDeviceLink/SDLTouchCoord.m
index ae0d5fde2..bba5b593c 100644
--- a/SmartDeviceLink/SDLTouchCoord.m
+++ b/SmartDeviceLink/SDLTouchCoord.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLTouchCoord
 
 - (void)setX:(NSNumber<SDLFloat> *)x {
@@ -26,3 +28,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLTouchEvent.h b/SmartDeviceLink/SDLTouchEvent.h
index 83a090b50..353b0a625 100644
--- a/SmartDeviceLink/SDLTouchEvent.h
+++ b/SmartDeviceLink/SDLTouchEvent.h
@@ -6,6 +6,8 @@
 
 @class SDLTouchCoord;
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLTouchEvent : SDLRPCStruct
 
 /**
@@ -15,7 +17,7 @@
  
  Mandatory, 0-9
  */
-@property (strong) NSNumber<SDLInt> *touchEventId;
+@property (strong, nonatomic) NSNumber<SDLInt> *touchEventId;
 
 /**
  The time that the touch was recorded.  This number can the time since the beginning of the session or something else as long as the units are in milliseconds.
@@ -28,11 +30,13 @@
  
  Mandatory, array size 1-1000, contains <NSNumber> size 0-5000000000
  */
-@property (strong) NSMutableArray<NSNumber<SDLInt> *> *timeStamp;
+@property (strong, nonatomic) NSMutableArray<NSNumber<SDLInt> *> *timeStamp;
 
 /**
  *  Mandatory, array size 1-1000, contains SDLTouchCoord
  */
-@property (strong) NSMutableArray<SDLTouchCoord *> *coord;
+@property (strong, nonatomic) NSMutableArray<SDLTouchCoord *> *coord;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLTouchEvent.m b/SmartDeviceLink/SDLTouchEvent.m
index e6abcbdc1..69616940b 100644
--- a/SmartDeviceLink/SDLTouchEvent.m
+++ b/SmartDeviceLink/SDLTouchEvent.m
@@ -8,6 +8,8 @@
 #import "SDLNames.h"
 #import "SDLTouchCoord.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLTouchEvent
 
 - (void)setTouchEventId:(NSNumber<SDLInt> *)touchEventId {
@@ -35,3 +37,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLTouchEventCapabilities.h b/SmartDeviceLink/SDLTouchEventCapabilities.h
index 40f37801a..87bb68bf4 100644
--- a/SmartDeviceLink/SDLTouchEventCapabilities.h
+++ b/SmartDeviceLink/SDLTouchEventCapabilities.h
@@ -4,10 +4,14 @@
 
 #import "SDLRPCMessage.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLTouchEventCapabilities : SDLRPCStruct
 
-@property (strong) NSNumber<SDLBool> *pressAvailable;
-@property (strong) NSNumber<SDLBool> *multiTouchAvailable;
-@property (strong) NSNumber<SDLBool> *doublePressAvailable;
+@property (strong, nonatomic) NSNumber<SDLBool> *pressAvailable;
+@property (strong, nonatomic) NSNumber<SDLBool> *multiTouchAvailable;
+@property (strong, nonatomic) NSNumber<SDLBool> *doublePressAvailable;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLTouchEventCapabilities.m b/SmartDeviceLink/SDLTouchEventCapabilities.m
index d13a6697f..cf019dc22 100644
--- a/SmartDeviceLink/SDLTouchEventCapabilities.m
+++ b/SmartDeviceLink/SDLTouchEventCapabilities.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLTouchEventCapabilities
 
 - (void)setPressAvailable:(NSNumber<SDLBool> *)pressAvailable {
@@ -34,3 +36,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLTransportDelegate.h b/SmartDeviceLink/SDLTransportDelegate.h
index 4f4abe33f..78d3d77c4 100644
--- a/SmartDeviceLink/SDLTransportDelegate.h
+++ b/SmartDeviceLink/SDLTransportDelegate.h
@@ -1,10 +1,14 @@
 //  SDLTransportDelegate.h
 //
 
+NS_ASSUME_NONNULL_BEGIN
+
 @protocol SDLTransportDelegate <NSObject>
 
 - (void)onTransportConnected;
 - (void)onTransportDisconnected;
 - (void)onDataReceived:(NSData *)receivedData;
 
-@end
\ No newline at end of file
+@end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLTurn.h b/SmartDeviceLink/SDLTurn.h
index 3b3a5b50a..f895d07eb 100644
--- a/SmartDeviceLink/SDLTurn.h
+++ b/SmartDeviceLink/SDLTurn.h
@@ -5,12 +5,15 @@
 
 @class SDLImage;
 
+NS_ASSUME_NONNULL_BEGIN
 
 @interface SDLTurn : SDLRPCStruct
 
-- (instancetype)initWithNavigationText:(NSString *)navigationText turnIcon:(SDLImage *)icon;
+- (instancetype)initWithNavigationText:(nullable NSString *)navigationText turnIcon:(nullable SDLImage *)icon;
 
-@property (strong) NSString *navigationText;
-@property (strong) SDLImage *turnIcon;
+@property (strong, nonatomic, nullable) NSString *navigationText;
+@property (strong, nonatomic, nullable) SDLImage *turnIcon;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLTurn.m b/SmartDeviceLink/SDLTurn.m
index 819d90466..335142782 100644
--- a/SmartDeviceLink/SDLTurn.m
+++ b/SmartDeviceLink/SDLTurn.m
@@ -7,10 +7,11 @@
 #import "SDLImage.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
 
 @implementation SDLTurn
 
-- (instancetype)initWithNavigationText:(NSString *)navigationText turnIcon:(SDLImage *)icon {
+- (instancetype)initWithNavigationText:(nullable NSString *)navigationText turnIcon:(nullable SDLImage *)icon {
     self = [self init];
     if (!self) {
         return nil;
@@ -22,20 +23,22 @@
     return self;
 }
 
-- (void)setNavigationText:(NSString *)navigationText {
+- (void)setNavigationText:(nullable NSString *)navigationText {
     [store sdl_setObject:navigationText forName:SDLNameNavigationText];
 }
 
-- (NSString *)navigationText {
+- (nullable NSString *)navigationText {
     return [store sdl_objectForName:SDLNameNavigationText];
 }
 
-- (void)setTurnIcon:(SDLImage *)turnIcon {
+- (void)setTurnIcon:(nullable SDLImage *)turnIcon {
     [store sdl_setObject:turnIcon forName:SDLNameTurnIcon];
 }
 
-- (SDLImage *)turnIcon {
+- (nullable SDLImage *)turnIcon {
     return [store sdl_objectForName:SDLNameTurnIcon ofClass:SDLImage.class];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLUnregisterAppInterface.h b/SmartDeviceLink/SDLUnregisterAppInterface.h
index 21c006127..35ca04639 100644
--- a/SmartDeviceLink/SDLUnregisterAppInterface.h
+++ b/SmartDeviceLink/SDLUnregisterAppInterface.h
@@ -19,6 +19,11 @@
  *
  * See SDLRegisterAppInterface SDLOnAppInterfaceUnregistered
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLUnregisterAppInterface : SDLRPCRequest
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLUnregisterAppInterface.m b/SmartDeviceLink/SDLUnregisterAppInterface.m
index acdf329f3..95520fca0 100644
--- a/SmartDeviceLink/SDLUnregisterAppInterface.m
+++ b/SmartDeviceLink/SDLUnregisterAppInterface.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLUnregisterAppInterface
 
 - (instancetype)init {
@@ -16,3 +18,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLUnregisterAppInterfaceResponse.h b/SmartDeviceLink/SDLUnregisterAppInterfaceResponse.h
index 1c6420f8e..c7088fc3e 100644
--- a/SmartDeviceLink/SDLUnregisterAppInterfaceResponse.h
+++ b/SmartDeviceLink/SDLUnregisterAppInterfaceResponse.h
@@ -9,6 +9,11 @@
  *
  * @since SmartDeviceLink 1.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLUnregisterAppInterfaceResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLUnregisterAppInterfaceResponse.m b/SmartDeviceLink/SDLUnregisterAppInterfaceResponse.m
index b11f488e0..77e93858b 100644
--- a/SmartDeviceLink/SDLUnregisterAppInterfaceResponse.m
+++ b/SmartDeviceLink/SDLUnregisterAppInterfaceResponse.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLUnregisterAppInterfaceResponse
 
 - (instancetype)init {
@@ -16,3 +18,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLUnsubscribeButton.h b/SmartDeviceLink/SDLUnsubscribeButton.h
index 59efd38bc..edfa5ae20 100644
--- a/SmartDeviceLink/SDLUnsubscribeButton.h
+++ b/SmartDeviceLink/SDLUnsubscribeButton.h
@@ -19,6 +19,9 @@
  * @since SmartDeviceLink 1.0<br/>
  * See SDLSubscribeButton
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLUnsubscribeButton : SDLRPCRequest
 
 - (instancetype)initWithButtonName:(SDLButtonName)buttonName;
@@ -28,6 +31,8 @@
  * @discussion An Enumeration value, see <i>
  *         SDLButtonName</i>
  */
-@property (strong) SDLButtonName buttonName;
+@property (strong, nonatomic) SDLButtonName buttonName;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLUnsubscribeButton.m b/SmartDeviceLink/SDLUnsubscribeButton.m
index a9543d8f3..1b1c18616 100644
--- a/SmartDeviceLink/SDLUnsubscribeButton.m
+++ b/SmartDeviceLink/SDLUnsubscribeButton.m
@@ -8,6 +8,8 @@
 #import "SDLButtonName.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLUnsubscribeButton
 
 - (instancetype)init {
@@ -36,3 +38,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLUnsubscribeButtonResponse.h b/SmartDeviceLink/SDLUnsubscribeButtonResponse.h
index 8dc43fad7..941cea512 100644
--- a/SmartDeviceLink/SDLUnsubscribeButtonResponse.h
+++ b/SmartDeviceLink/SDLUnsubscribeButtonResponse.h
@@ -9,6 +9,11 @@
  *
  * @since SmartDeviceLink 1.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLUnsubscribeButtonResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLUnsubscribeButtonResponse.m b/SmartDeviceLink/SDLUnsubscribeButtonResponse.m
index 037efdd11..e92565e58 100644
--- a/SmartDeviceLink/SDLUnsubscribeButtonResponse.m
+++ b/SmartDeviceLink/SDLUnsubscribeButtonResponse.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLUnsubscribeButtonResponse
 
 - (instancetype)init {
@@ -16,3 +18,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLUnsubscribeVehicleData.h b/SmartDeviceLink/SDLUnsubscribeVehicleData.h
index b16ae1f42..fc7938075 100644
--- a/SmartDeviceLink/SDLUnsubscribeVehicleData.h
+++ b/SmartDeviceLink/SDLUnsubscribeVehicleData.h
@@ -16,6 +16,9 @@
  * @since SmartDeviceLink 2.0<br/>
  * See SDLSubscribeVehicleData SDLGetVehicleData
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLUnsubscribeVehicleData : SDLRPCRequest
 
 - (instancetype)initWithAccelerationPedalPosition:(BOOL)accelerationPedalPosition airbagStatus:(BOOL)airbagStatus beltStatus:(BOOL)beltStatus bodyInformation:(BOOL)bodyInformation clusterModeStatus:(BOOL)clusterModeStatus deviceStatus:(BOOL)deviceStatus driverBraking:(BOOL)driverBraking eCallInfo:(BOOL)eCallInfo emergencyEvent:(BOOL)emergencyEvent engineTorque:(BOOL)engineTorque externalTemperature:(BOOL)externalTemperature fuelLevel:(BOOL)fuelLevel fuelLevelState:(BOOL)fuelLevelState gps:(BOOL)gps headLampStatus:(BOOL)headLampStatus instantFuelConsumption:(BOOL)instantFuelConsumption myKey:(BOOL)myKey odometer:(BOOL)odometer prndl:(BOOL)prndl rpm:(BOOL)rpm speed:(BOOL)speed steeringWheelAngle:(BOOL)steeringWheelAngle tirePressure:(BOOL)tirePressure wiperStatus:(BOOL)wiperStatus;
@@ -23,97 +26,99 @@
 /**
  * @abstract A boolean value. If true, unsubscribes Gps data
  */
-@property (strong) NSNumber<SDLBool> *gps;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *gps;
 
 /**
  * @abstract A boolean value. If true, unsubscribes speed data
  */
-@property (strong) NSNumber<SDLBool> *speed;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *speed;
 
 /**
  * @abstract A boolean value. If true, unsubscribe data
  */
-@property (strong) NSNumber<SDLBool> *rpm;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *rpm;
 
 /**
  * @abstract A boolean value. If true, unsubscribes FuelLevel data
  */
-@property (strong) NSNumber<SDLBool> *fuelLevel;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *fuelLevel;
 
 /**
  * @abstract A boolean value. If true, unsubscribes fuelLevel_State data
  */
-@property (strong) NSNumber<SDLBool> *fuelLevel_State;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *fuelLevel_State;
 
 /**
  * @abstract A boolean value. If true, unsubscribes instantFuelConsumption data
  */
-@property (strong) NSNumber<SDLBool> *instantFuelConsumption;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *instantFuelConsumption;
 
 /**
  * @abstract A boolean value. If true, unsubscribes externalTemperature data
  */
-@property (strong) NSNumber<SDLBool> *externalTemperature;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *externalTemperature;
 
 /**
  * @abstract A boolean value. If true, unsubscribes Currently selected gear data
  */
-@property (strong) NSNumber<SDLBool> *prndl;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *prndl;
 
 /**
  * @abstract A boolean value. If true, unsubscribes tire pressure status data
  */
-@property (strong) NSNumber<SDLBool> *tirePressure;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *tirePressure;
 
 /**
  * @abstract A boolean value. If true, unsubscribes odometer data
  */
-@property (strong) NSNumber<SDLBool> *odometer;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *odometer;
 
 /**
  * @abstract A boolean value. If true, unsubscribes belt Status data
  */
-@property (strong) NSNumber<SDLBool> *beltStatus;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *beltStatus;
 
 /**
  * @abstract A boolean value. If true, unsubscribes body Information data
  */
-@property (strong) NSNumber<SDLBool> *bodyInformation;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *bodyInformation;
 
 /**
  * @abstract A boolean value. If true, unsubscribes device Status data
  */
-@property (strong) NSNumber<SDLBool> *deviceStatus;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *deviceStatus;
 
 /**
  * @abstract A boolean value. If true, unsubscribes driver Braking data
  */
-@property (strong) NSNumber<SDLBool> *driverBraking;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *driverBraking;
 
 /**
  * @abstract A boolean value. If true, unsubscribes wiper Status data
  */
-@property (strong) NSNumber<SDLBool> *wiperStatus;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *wiperStatus;
 
 /**
  * @abstract A boolean value. If true, unsubscribes Head Lamp Status data
  */
-@property (strong) NSNumber<SDLBool> *headLampStatus;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *headLampStatus;
 
 /**
  * @abstract A boolean value. If true, unsubscribes Engine Torque data
  */
-@property (strong) NSNumber<SDLBool> *engineTorque;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *engineTorque;
 
 /**
  * @abstract A boolean value. If true, unsubscribes accPedalPosition data
  */
-@property (strong) NSNumber<SDLBool> *accPedalPosition;
-@property (strong) NSNumber<SDLBool> *steeringWheelAngle;
-@property (strong) NSNumber<SDLBool> *eCallInfo;
-@property (strong) NSNumber<SDLBool> *airbagStatus;
-@property (strong) NSNumber<SDLBool> *emergencyEvent;
-@property (strong) NSNumber<SDLBool> *clusterModeStatus;
-@property (strong) NSNumber<SDLBool> *myKey;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *accPedalPosition;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *steeringWheelAngle;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *eCallInfo;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *airbagStatus;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *emergencyEvent;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *clusterModeStatus;
+@property (strong, nonatomic, nullable) NSNumber<SDLBool> *myKey;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLUnsubscribeVehicleData.m b/SmartDeviceLink/SDLUnsubscribeVehicleData.m
index b4567ca7a..ec5312268 100644
--- a/SmartDeviceLink/SDLUnsubscribeVehicleData.m
+++ b/SmartDeviceLink/SDLUnsubscribeVehicleData.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLUnsubscribeVehicleData
 
 - (instancetype)init {
@@ -49,196 +51,198 @@
     return self;
 }
 
-- (void)setGps:(NSNumber<SDLBool> *)gps {
+- (void)setGps:(nullable NSNumber<SDLBool> *)gps {
     [parameters sdl_setObject:gps forName:SDLNameGPS];
 }
 
-- (NSNumber<SDLBool> *)gps {
+- (nullable NSNumber<SDLBool> *)gps {
     return [parameters sdl_objectForName:SDLNameGPS];
 }
 
-- (void)setSpeed:(NSNumber<SDLBool> *)speed {
+- (void)setSpeed:(nullable NSNumber<SDLBool> *)speed {
     [parameters sdl_setObject:speed forName:SDLNameSpeed];
 }
 
-- (NSNumber<SDLBool> *)speed {
+- (nullable NSNumber<SDLBool> *)speed {
     return [parameters sdl_objectForName:SDLNameSpeed];
 }
 
-- (void)setRpm:(NSNumber<SDLBool> *)rpm {
+- (void)setRpm:(nullable NSNumber<SDLBool> *)rpm {
     [parameters sdl_setObject:rpm forName:SDLNameRPM];
 }
 
-- (NSNumber<SDLBool> *)rpm {
+- (nullable NSNumber<SDLBool> *)rpm {
     return [parameters sdl_objectForName:SDLNameRPM];
 }
 
-- (void)setFuelLevel:(NSNumber<SDLBool> *)fuelLevel {
+- (void)setFuelLevel:(nullable NSNumber<SDLBool> *)fuelLevel {
     [parameters sdl_setObject:fuelLevel forName:SDLNameFuelLevel];
 }
 
-- (NSNumber<SDLBool> *)fuelLevel {
+- (nullable NSNumber<SDLBool> *)fuelLevel {
     return [parameters sdl_objectForName:SDLNameFuelLevel];
 }
 
-- (void)setFuelLevel_State:(NSNumber<SDLBool> *)fuelLevel_State {
+- (void)setFuelLevel_State:(nullable NSNumber<SDLBool> *)fuelLevel_State {
     [parameters sdl_setObject:fuelLevel_State forName:SDLNameFuelLevelState];
 }
 
-- (NSNumber<SDLBool> *)fuelLevel_State {
+- (nullable NSNumber<SDLBool> *)fuelLevel_State {
     return [parameters sdl_objectForName:SDLNameFuelLevelState];
 }
 
-- (void)setInstantFuelConsumption:(NSNumber<SDLBool> *)instantFuelConsumption {
+- (void)setInstantFuelConsumption:(nullable NSNumber<SDLBool> *)instantFuelConsumption {
     [parameters sdl_setObject:instantFuelConsumption forName:SDLNameInstantFuelConsumption];
 }
 
-- (NSNumber<SDLBool> *)instantFuelConsumption {
+- (nullable NSNumber<SDLBool> *)instantFuelConsumption {
     return [parameters sdl_objectForName:SDLNameInstantFuelConsumption];
 }
 
-- (void)setExternalTemperature:(NSNumber<SDLBool> *)externalTemperature {
+- (void)setExternalTemperature:(nullable NSNumber<SDLBool> *)externalTemperature {
     [parameters sdl_setObject:externalTemperature forName:SDLNameExternalTemperature];
 }
 
-- (NSNumber<SDLBool> *)externalTemperature {
+- (nullable NSNumber<SDLBool> *)externalTemperature {
     return [parameters sdl_objectForName:SDLNameExternalTemperature];
 }
 
-- (void)setPrndl:(NSNumber<SDLBool> *)prndl {
+- (void)setPrndl:(nullable NSNumber<SDLBool> *)prndl {
     [parameters sdl_setObject:prndl forName:SDLNamePRNDL];
 }
 
-- (NSNumber<SDLBool> *)prndl {
+- (nullable NSNumber<SDLBool> *)prndl {
     return [parameters sdl_objectForName:SDLNamePRNDL];
 }
 
-- (void)setTirePressure:(NSNumber<SDLBool> *)tirePressure {
+- (void)setTirePressure:(nullable NSNumber<SDLBool> *)tirePressure {
     [parameters sdl_setObject:tirePressure forName:SDLNameTirePressure];
 }
 
-- (NSNumber<SDLBool> *)tirePressure {
+- (nullable NSNumber<SDLBool> *)tirePressure {
     return [parameters sdl_objectForName:SDLNameTirePressure];
 }
 
-- (void)setOdometer:(NSNumber<SDLBool> *)odometer {
+- (void)setOdometer:(nullable NSNumber<SDLBool> *)odometer {
     [parameters sdl_setObject:odometer forName:SDLNameOdometer];
 }
 
-- (NSNumber<SDLBool> *)odometer {
+- (nullable NSNumber<SDLBool> *)odometer {
     return [parameters sdl_objectForName:SDLNameOdometer];
 }
 
-- (void)setBeltStatus:(NSNumber<SDLBool> *)beltStatus {
+- (void)setBeltStatus:(nullable NSNumber<SDLBool> *)beltStatus {
     [parameters sdl_setObject:beltStatus forName:SDLNameBeltStatus];
 }
 
-- (NSNumber<SDLBool> *)beltStatus {
+- (nullable NSNumber<SDLBool> *)beltStatus {
     return [parameters sdl_objectForName:SDLNameBeltStatus];
 }
 
-- (void)setBodyInformation:(NSNumber<SDLBool> *)bodyInformation {
+- (void)setBodyInformation:(nullable NSNumber<SDLBool> *)bodyInformation {
     [parameters sdl_setObject:bodyInformation forName:SDLNameBodyInformation];
 }
 
-- (NSNumber<SDLBool> *)bodyInformation {
+- (nullable NSNumber<SDLBool> *)bodyInformation {
     return [parameters sdl_objectForName:SDLNameBodyInformation];
 }
 
-- (void)setDeviceStatus:(NSNumber<SDLBool> *)deviceStatus {
+- (void)setDeviceStatus:(nullable NSNumber<SDLBool> *)deviceStatus {
     [parameters sdl_setObject:deviceStatus forName:SDLNameDeviceStatus];
 }
 
-- (NSNumber<SDLBool> *)deviceStatus {
+- (nullable NSNumber<SDLBool> *)deviceStatus {
     return [parameters sdl_objectForName:SDLNameDeviceStatus];
 }
 
-- (void)setDriverBraking:(NSNumber<SDLBool> *)driverBraking {
+- (void)setDriverBraking:(nullable NSNumber<SDLBool> *)driverBraking {
     [parameters sdl_setObject:driverBraking forName:SDLNameDriverBraking];
 }
 
-- (NSNumber<SDLBool> *)driverBraking {
+- (nullable NSNumber<SDLBool> *)driverBraking {
     return [parameters sdl_objectForName:SDLNameDriverBraking];
 }
 
-- (void)setWiperStatus:(NSNumber<SDLBool> *)wiperStatus {
+- (void)setWiperStatus:(nullable NSNumber<SDLBool> *)wiperStatus {
     [parameters sdl_setObject:wiperStatus forName:SDLNameWiperStatus];
 }
 
-- (NSNumber<SDLBool> *)wiperStatus {
+- (nullable NSNumber<SDLBool> *)wiperStatus {
     return [parameters sdl_objectForName:SDLNameWiperStatus];
 }
 
-- (void)setHeadLampStatus:(NSNumber<SDLBool> *)headLampStatus {
+- (void)setHeadLampStatus:(nullable NSNumber<SDLBool> *)headLampStatus {
     [parameters sdl_setObject:headLampStatus forName:SDLNameHeadLampStatus];
 }
 
-- (NSNumber<SDLBool> *)headLampStatus {
+- (nullable NSNumber<SDLBool> *)headLampStatus {
     return [parameters sdl_objectForName:SDLNameHeadLampStatus];
 }
 
-- (void)setEngineTorque:(NSNumber<SDLBool> *)engineTorque {
+- (void)setEngineTorque:(nullable NSNumber<SDLBool> *)engineTorque {
     [parameters sdl_setObject:engineTorque forName:SDLNameEngineTorque];
 }
 
-- (NSNumber<SDLBool> *)engineTorque {
+- (nullable NSNumber<SDLBool> *)engineTorque {
     return [parameters sdl_objectForName:SDLNameEngineTorque];
 }
 
-- (void)setAccPedalPosition:(NSNumber<SDLBool> *)accPedalPosition {
+- (void)setAccPedalPosition:(nullable NSNumber<SDLBool> *)accPedalPosition {
     [parameters sdl_setObject:accPedalPosition forName:SDLNameAccelerationPedalPosition];
 }
 
-- (NSNumber<SDLBool> *)accPedalPosition {
+- (nullable NSNumber<SDLBool> *)accPedalPosition {
     return [parameters sdl_objectForName:SDLNameAccelerationPedalPosition];
 }
 
-- (void)setSteeringWheelAngle:(NSNumber<SDLBool> *)steeringWheelAngle {
+- (void)setSteeringWheelAngle:(nullable NSNumber<SDLBool> *)steeringWheelAngle {
     [parameters sdl_setObject:steeringWheelAngle forName:SDLNameSteeringWheelAngle];
 }
 
-- (NSNumber<SDLBool> *)steeringWheelAngle {
+- (nullable NSNumber<SDLBool> *)steeringWheelAngle {
     return [parameters sdl_objectForName:SDLNameSteeringWheelAngle];
 }
 
-- (void)setECallInfo:(NSNumber<SDLBool> *)eCallInfo {
+- (void)setECallInfo:(nullable NSNumber<SDLBool> *)eCallInfo {
     [parameters sdl_setObject:eCallInfo forName:SDLNameECallInfo];
 }
 
-- (NSNumber<SDLBool> *)eCallInfo {
+- (nullable NSNumber<SDLBool> *)eCallInfo {
     return [parameters sdl_objectForName:SDLNameECallInfo];
 }
 
-- (void)setAirbagStatus:(NSNumber<SDLBool> *)airbagStatus {
+- (void)setAirbagStatus:(nullable NSNumber<SDLBool> *)airbagStatus {
     [parameters sdl_setObject:airbagStatus forName:SDLNameAirbagStatus];
 }
 
-- (NSNumber<SDLBool> *)airbagStatus {
+- (nullable NSNumber<SDLBool> *)airbagStatus {
     return [parameters sdl_objectForName:SDLNameAirbagStatus];
 }
 
-- (void)setEmergencyEvent:(NSNumber<SDLBool> *)emergencyEvent {
+- (void)setEmergencyEvent:(nullable NSNumber<SDLBool> *)emergencyEvent {
     [parameters sdl_setObject:emergencyEvent forName:SDLNameEmergencyEvent];
 }
 
-- (NSNumber<SDLBool> *)emergencyEvent {
+- (nullable NSNumber<SDLBool> *)emergencyEvent {
     return [parameters sdl_objectForName:SDLNameEmergencyEvent];
 }
 
-- (void)setClusterModeStatus:(NSNumber<SDLBool> *)clusterModeStatus {
+- (void)setClusterModeStatus:(nullable NSNumber<SDLBool> *)clusterModeStatus {
     [parameters sdl_setObject:clusterModeStatus forName:SDLNameClusterModeStatus];
 }
 
-- (NSNumber<SDLBool> *)clusterModeStatus {
+- (nullable NSNumber<SDLBool> *)clusterModeStatus {
     return [parameters sdl_objectForName:SDLNameClusterModeStatus];
 }
 
-- (void)setMyKey:(NSNumber<SDLBool> *)myKey {
+- (void)setMyKey:(nullable NSNumber<SDLBool> *)myKey {
     [parameters sdl_setObject:myKey forName:SDLNameMyKey];
 }
 
-- (NSNumber<SDLBool> *)myKey {
+- (nullable NSNumber<SDLBool> *)myKey {
     return [parameters sdl_objectForName:SDLNameMyKey];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLUnsubscribeVehicleDataResponse.h b/SmartDeviceLink/SDLUnsubscribeVehicleDataResponse.h
index eecce7b75..bced5894e 100644
--- a/SmartDeviceLink/SDLUnsubscribeVehicleDataResponse.h
+++ b/SmartDeviceLink/SDLUnsubscribeVehicleDataResponse.h
@@ -11,106 +11,111 @@
  *
  * @since SmartDeviceLink 2.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLUnsubscribeVehicleDataResponse : SDLRPCResponse
 
 /**
  * @abstract A SDLVehicleDataResult* value. See GPSData.
  */
-@property (strong) SDLVehicleDataResult *gps;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *gps;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The vehicle speed in kilometers per hour.
  */
-@property (strong) SDLVehicleDataResult *speed;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *speed;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The number of revolutions per minute of the engine.
  */
-@property (strong) SDLVehicleDataResult *rpm;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *rpm;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The fuel level in the tank (percentage)
  */
-@property (strong) SDLVehicleDataResult *fuelLevel;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *fuelLevel;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The fuel level state.
  */
-@property (strong) SDLVehicleDataResult *fuelLevel_State;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *fuelLevel_State;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The instantaneous fuel consumption in microlitres.
  */
-@property (strong) SDLVehicleDataResult *instantFuelConsumption;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *instantFuelConsumption;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The external temperature in degrees celsius.
  */
-@property (strong) SDLVehicleDataResult *externalTemperature;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *externalTemperature;
 
 /**
  * @abstract A SDLVehicleDataResult* value. See PRNDL.
  */
-@property (strong) SDLVehicleDataResult *prndl;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *prndl;
 
 /**
  * @abstract A SDLVehicleDataResult* value. See TireStatus.
  */
-@property (strong) SDLVehicleDataResult *tirePressure;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *tirePressure;
 
 /**
  * @abstract A SDLVehicleDataResult* value. Odometer in km.
  */
-@property (strong) SDLVehicleDataResult *odometer;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *odometer;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The status of the seat belts.
  */
-@property (strong) SDLVehicleDataResult *beltStatus;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *beltStatus;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The body information including power modes.
  */
-@property (strong) SDLVehicleDataResult *bodyInformation;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *bodyInformation;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The device status including signal and battery strength.
  */
-@property (strong) SDLVehicleDataResult *deviceStatus;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *deviceStatus;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The status of the brake pedal.
  */
-@property (strong) SDLVehicleDataResult *driverBraking;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *driverBraking;
 
 /**
  * @abstract A SDLVehicleDataResult* value. The status of the wipers.
  */
-@property (strong) SDLVehicleDataResult *wiperStatus;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *wiperStatus;
 
 /**
  * @abstract A SDLVehicleDataResult* value. Status of the head lamps.
  */
-@property (strong) SDLVehicleDataResult *headLampStatus;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *headLampStatus;
 
 /**
  * @abstract A SDLVehicleDataResult* value. Torque value for engine (in Nm) on non-diesel variants.
  */
-@property (strong) SDLVehicleDataResult *engineTorque;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *engineTorque;
 
 /**
  * @abstract A SDLVehicleDataResult* value. Accelerator pedal position (percentage depressed)
  */
-@property (strong) SDLVehicleDataResult *accPedalPosition;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *accPedalPosition;
 
 /**
  * @abstract A SDLVehicleDataResult* value. Current angle of the steering wheel (in deg)
  */
-@property (strong) SDLVehicleDataResult *steeringWheelAngle;
-@property (strong) SDLVehicleDataResult *eCallInfo;
-@property (strong) SDLVehicleDataResult *airbagStatus;
-@property (strong) SDLVehicleDataResult *emergencyEvent;
-@property (strong) SDLVehicleDataResult *clusterModes;
-@property (strong) SDLVehicleDataResult *myKey;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *steeringWheelAngle;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *eCallInfo;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *airbagStatus;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *emergencyEvent;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *clusterModes;
+@property (strong, nonatomic, nullable) SDLVehicleDataResult *myKey;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLUnsubscribeVehicleDataResponse.m b/SmartDeviceLink/SDLUnsubscribeVehicleDataResponse.m
index b5a138ad7..5eb911d42 100644
--- a/SmartDeviceLink/SDLUnsubscribeVehicleDataResponse.m
+++ b/SmartDeviceLink/SDLUnsubscribeVehicleDataResponse.m
@@ -8,6 +8,8 @@
 #import "SDLNames.h"
 #import "SDLVehicleDataResult.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLUnsubscribeVehicleDataResponse
 
 - (instancetype)init {
@@ -16,197 +18,199 @@
     return self;
 }
 
-- (void)setGps:(SDLVehicleDataResult *)gps {
+- (void)setGps:(nullable SDLVehicleDataResult *)gps {
     [parameters sdl_setObject:gps forName:SDLNameGPS];
 }
 
-- (SDLVehicleDataResult *)gps {
+- (nullable SDLVehicleDataResult *)gps {
     return [parameters sdl_objectForName:SDLNameGPS ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setSpeed:(SDLVehicleDataResult *)speed {
+- (void)setSpeed:(nullable SDLVehicleDataResult *)speed {
     [parameters sdl_setObject:speed forName:SDLNameSpeed];
 }
 
-- (SDLVehicleDataResult *)speed {
+- (nullable SDLVehicleDataResult *)speed {
     return [parameters sdl_objectForName:SDLNameSpeed ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setRpm:(SDLVehicleDataResult *)rpm {
+- (void)setRpm:(nullable SDLVehicleDataResult *)rpm {
     [parameters sdl_setObject:rpm forName:SDLNameRPM];
 }
 
-- (SDLVehicleDataResult *)rpm {
+- (nullable SDLVehicleDataResult *)rpm {
     return [parameters sdl_objectForName:SDLNameRPM ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setFuelLevel:(SDLVehicleDataResult *)fuelLevel {
+- (void)setFuelLevel:(nullable SDLVehicleDataResult *)fuelLevel {
     [parameters sdl_setObject:fuelLevel forName:SDLNameFuelLevel];
 }
 
-- (SDLVehicleDataResult *)fuelLevel {
+- (nullable SDLVehicleDataResult *)fuelLevel {
     return [parameters sdl_objectForName:SDLNameFuelLevel ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setFuelLevel_State:(SDLVehicleDataResult *)fuelLevel_State {
+- (void)setFuelLevel_State:(nullable SDLVehicleDataResult *)fuelLevel_State {
     [parameters sdl_setObject:fuelLevel_State forName:SDLNameFuelLevelState];
 }
 
-- (SDLVehicleDataResult *)fuelLevel_State {
+- (nullable SDLVehicleDataResult *)fuelLevel_State {
     return [parameters sdl_objectForName:SDLNameFuelLevelState ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setInstantFuelConsumption:(SDLVehicleDataResult *)instantFuelConsumption {
+- (void)setInstantFuelConsumption:(nullable SDLVehicleDataResult *)instantFuelConsumption {
     [parameters sdl_setObject:instantFuelConsumption forName:SDLNameInstantFuelConsumption];
 }
 
-- (SDLVehicleDataResult *)instantFuelConsumption {
+- (nullable SDLVehicleDataResult *)instantFuelConsumption {
     return [parameters sdl_objectForName:SDLNameInstantFuelConsumption ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setExternalTemperature:(SDLVehicleDataResult *)externalTemperature {
+- (void)setExternalTemperature:(nullable SDLVehicleDataResult *)externalTemperature {
     [parameters sdl_setObject:externalTemperature forName:SDLNameExternalTemperature];
 }
 
-- (SDLVehicleDataResult *)externalTemperature {
+- (nullable SDLVehicleDataResult *)externalTemperature {
     return [parameters sdl_objectForName:SDLNameExternalTemperature ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setPrndl:(SDLVehicleDataResult *)prndl {
+- (void)setPrndl:(nullable SDLVehicleDataResult *)prndl {
     [parameters sdl_setObject:prndl forName:SDLNamePRNDL];
 }
 
-- (SDLVehicleDataResult *)prndl {
+- (nullable SDLVehicleDataResult *)prndl {
     return [parameters sdl_objectForName:SDLNamePRNDL ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setTirePressure:(SDLVehicleDataResult *)tirePressure {
+- (void)setTirePressure:(nullable SDLVehicleDataResult *)tirePressure {
     [parameters sdl_setObject:tirePressure forName:SDLNameTirePressure];
 }
 
-- (SDLVehicleDataResult *)tirePressure {
+- (nullable SDLVehicleDataResult *)tirePressure {
     return [parameters sdl_objectForName:SDLNameTirePressure ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setOdometer:(SDLVehicleDataResult *)odometer {
+- (void)setOdometer:(nullable SDLVehicleDataResult *)odometer {
     [parameters sdl_setObject:odometer forName:SDLNameOdometer];
 }
 
-- (SDLVehicleDataResult *)odometer {
+- (nullable SDLVehicleDataResult *)odometer {
     return [parameters sdl_objectForName:SDLNameOdometer ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setBeltStatus:(SDLVehicleDataResult *)beltStatus {
+- (void)setBeltStatus:(nullable SDLVehicleDataResult *)beltStatus {
     [parameters sdl_setObject:beltStatus forName:SDLNameBeltStatus];
 }
 
-- (SDLVehicleDataResult *)beltStatus {
+- (nullable SDLVehicleDataResult *)beltStatus {
     return [parameters sdl_objectForName:SDLNameBeltStatus ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setBodyInformation:(SDLVehicleDataResult *)bodyInformation {
+- (void)setBodyInformation:(nullable SDLVehicleDataResult *)bodyInformation {
     [parameters sdl_setObject:bodyInformation forName:SDLNameBodyInformation];
 }
 
-- (SDLVehicleDataResult *)bodyInformation {
+- (nullable SDLVehicleDataResult *)bodyInformation {
     return [parameters sdl_objectForName:SDLNameBodyInformation ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setDeviceStatus:(SDLVehicleDataResult *)deviceStatus {
+- (void)setDeviceStatus:(nullable SDLVehicleDataResult *)deviceStatus {
     [parameters sdl_setObject:deviceStatus forName:SDLNameDeviceStatus];
 }
 
-- (SDLVehicleDataResult *)deviceStatus {
+- (nullable SDLVehicleDataResult *)deviceStatus {
     return [parameters sdl_objectForName:SDLNameDeviceStatus ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setDriverBraking:(SDLVehicleDataResult *)driverBraking {
+- (void)setDriverBraking:(nullable SDLVehicleDataResult *)driverBraking {
     [parameters sdl_setObject:driverBraking forName:SDLNameDriverBraking];
 }
 
-- (SDLVehicleDataResult *)driverBraking {
+- (nullable SDLVehicleDataResult *)driverBraking {
     return [parameters sdl_objectForName:SDLNameDriverBraking ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setWiperStatus:(SDLVehicleDataResult *)wiperStatus {
+- (void)setWiperStatus:(nullable SDLVehicleDataResult *)wiperStatus {
     [parameters sdl_setObject:wiperStatus forName:SDLNameWiperStatus];
 }
 
-- (SDLVehicleDataResult *)wiperStatus {
+- (nullable SDLVehicleDataResult *)wiperStatus {
     return [parameters sdl_objectForName:SDLNameWiperStatus ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setHeadLampStatus:(SDLVehicleDataResult *)headLampStatus {
+- (void)setHeadLampStatus:(nullable SDLVehicleDataResult *)headLampStatus {
     [parameters sdl_setObject:headLampStatus forName:SDLNameHeadLampStatus];
 }
 
-- (SDLVehicleDataResult *)headLampStatus {
+- (nullable SDLVehicleDataResult *)headLampStatus {
     return [parameters sdl_objectForName:SDLNameHeadLampStatus ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setEngineTorque:(SDLVehicleDataResult *)engineTorque {
+- (void)setEngineTorque:(nullable SDLVehicleDataResult *)engineTorque {
     [parameters sdl_setObject:engineTorque forName:SDLNameEngineTorque];
 }
 
-- (SDLVehicleDataResult *)engineTorque {
+- (nullable SDLVehicleDataResult *)engineTorque {
     return [parameters sdl_objectForName:SDLNameEngineTorque ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setAccPedalPosition:(SDLVehicleDataResult *)accPedalPosition {
+- (void)setAccPedalPosition:(nullable SDLVehicleDataResult *)accPedalPosition {
     [parameters sdl_setObject:accPedalPosition forName:SDLNameAccelerationPedalPosition];
 }
 
-- (SDLVehicleDataResult *)accPedalPosition {
+- (nullable SDLVehicleDataResult *)accPedalPosition {
     return [parameters sdl_objectForName:SDLNameAccelerationPedalPosition ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setSteeringWheelAngle:(SDLVehicleDataResult *)steeringWheelAngle {
+- (void)setSteeringWheelAngle:(nullable SDLVehicleDataResult *)steeringWheelAngle {
     [parameters sdl_setObject:steeringWheelAngle forName:SDLNameSteeringWheelAngle];
 }
 
-- (SDLVehicleDataResult *)steeringWheelAngle {
+- (nullable SDLVehicleDataResult *)steeringWheelAngle {
     return [parameters sdl_objectForName:SDLNameSteeringWheelAngle ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setECallInfo:(SDLVehicleDataResult *)eCallInfo {
+- (void)setECallInfo:(nullable SDLVehicleDataResult *)eCallInfo {
     [parameters sdl_setObject:eCallInfo forName:SDLNameECallInfo];
 }
 
-- (SDLVehicleDataResult *)eCallInfo {
+- (nullable SDLVehicleDataResult *)eCallInfo {
     return [parameters sdl_objectForName:SDLNameECallInfo ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setAirbagStatus:(SDLVehicleDataResult *)airbagStatus {
+- (void)setAirbagStatus:(nullable SDLVehicleDataResult *)airbagStatus {
     [parameters sdl_setObject:airbagStatus forName:SDLNameAirbagStatus];
 }
 
-- (SDLVehicleDataResult *)airbagStatus {
+- (nullable SDLVehicleDataResult *)airbagStatus {
     return [parameters sdl_objectForName:SDLNameAirbagStatus ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setEmergencyEvent:(SDLVehicleDataResult *)emergencyEvent {
+- (void)setEmergencyEvent:(nullable SDLVehicleDataResult *)emergencyEvent {
     [parameters sdl_setObject:emergencyEvent forName:SDLNameEmergencyEvent];
 }
 
-- (SDLVehicleDataResult *)emergencyEvent {
+- (nullable SDLVehicleDataResult *)emergencyEvent {
     return [parameters sdl_objectForName:SDLNameEmergencyEvent ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setClusterModes:(SDLVehicleDataResult *)clusterModes {
+- (void)setClusterModes:(nullable SDLVehicleDataResult *)clusterModes {
     [parameters sdl_setObject:clusterModes forName:SDLNameClusterModes];
 }
 
-- (SDLVehicleDataResult *)clusterModes {
+- (nullable SDLVehicleDataResult *)clusterModes {
     return [parameters sdl_objectForName:SDLNameClusterModes ofClass:SDLVehicleDataResult.class];
 }
 
-- (void)setMyKey:(SDLVehicleDataResult *)myKey {
+- (void)setMyKey:(nullable SDLVehicleDataResult *)myKey {
     [parameters sdl_setObject:myKey forName:SDLNameMyKey];
 }
 
-- (SDLVehicleDataResult *)myKey {
+- (nullable SDLVehicleDataResult *)myKey {
     return [parameters sdl_objectForName:SDLNameMyKey ofClass:SDLVehicleDataResult.class];
 }
 
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLUnsubscribeWaypoints.h b/SmartDeviceLink/SDLUnsubscribeWaypoints.h
index d5e477ad7..e76db6580 100644
--- a/SmartDeviceLink/SDLUnsubscribeWaypoints.h
+++ b/SmartDeviceLink/SDLUnsubscribeWaypoints.h
@@ -3,10 +3,18 @@
 
 #import "SDLRPCRequest.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLUnsubscribeWayPoints : SDLRPCRequest
 
 @end
 
+NS_ASSUME_NONNULL_END
+
+NS_ASSUME_NONNULL_BEGIN
+
 __deprecated_msg("Use SDLUnsubscribeWayPoints instead")
-    @interface SDLUnsubscribeWaypoints : SDLUnsubscribeWayPoints
-                                         @end
+@interface SDLUnsubscribeWaypoints : SDLUnsubscribeWayPoints
+@end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLUnsubscribeWaypoints.m b/SmartDeviceLink/SDLUnsubscribeWaypoints.m
index 6dc36fb29..74ba51f9a 100644
--- a/SmartDeviceLink/SDLUnsubscribeWaypoints.m
+++ b/SmartDeviceLink/SDLUnsubscribeWaypoints.m
@@ -6,6 +6,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLUnsubscribeWayPoints
 
 - (instancetype)init {
@@ -16,6 +18,12 @@
 
 @end
 
+NS_ASSUME_NONNULL_END
+
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLUnsubscribeWaypoints
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLUnsubscribeWaypointsResponse.h b/SmartDeviceLink/SDLUnsubscribeWaypointsResponse.h
index 11a9e7961..f6c981b52 100644
--- a/SmartDeviceLink/SDLUnsubscribeWaypointsResponse.h
+++ b/SmartDeviceLink/SDLUnsubscribeWaypointsResponse.h
@@ -3,10 +3,14 @@
 
 #import "SDLRPCResponse.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLUnsubscribeWayPointsResponse : SDLRPCResponse
 
 @end
 
 __deprecated_msg("Use SDLUnsubscribeWayPointsResponse instead")
-    @interface SDLUnsubscribeWaypointsResponse : SDLUnsubscribeWayPointsResponse
-                                                 @end
+@interface SDLUnsubscribeWaypointsResponse : SDLUnsubscribeWayPointsResponse
+@end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLUnsubscribeWaypointsResponse.m b/SmartDeviceLink/SDLUnsubscribeWaypointsResponse.m
index 92431bacf..77d5fcebf 100644
--- a/SmartDeviceLink/SDLUnsubscribeWaypointsResponse.m
+++ b/SmartDeviceLink/SDLUnsubscribeWaypointsResponse.m
@@ -6,6 +6,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLUnsubscribeWayPointsResponse
 
 - (instancetype)init {
@@ -19,3 +21,5 @@
 @implementation SDLUnsubscribeWaypointsResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLUpdateTurnList.h b/SmartDeviceLink/SDLUpdateTurnList.h
index 873459967..63a3473aa 100644
--- a/SmartDeviceLink/SDLUpdateTurnList.h
+++ b/SmartDeviceLink/SDLUpdateTurnList.h
@@ -12,18 +12,23 @@
  *<p>
  * @since SmartDeviceLink 2.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLUpdateTurnList : SDLRPCRequest
 
-- (instancetype)initWithTurnList:(NSArray<SDLTurn *> *)turnList softButtons:(NSArray<SDLSoftButton *> *)softButtons;
+- (instancetype)initWithTurnList:(nullable NSArray<SDLTurn *> *)turnList softButtons:(nullable NSArray<SDLSoftButton *> *)softButtons;
 
 /**
  *  Optional, SDLTurn, 1 - 100 entries
  */
-@property (strong) NSMutableArray<SDLTurn *> *turnList;
+@property (strong, nonatomic, nullable) NSMutableArray<SDLTurn *> *turnList;
 
 /**
  *  Required, SDLSoftButton, 0 - 1 Entries
  */
-@property (strong) NSMutableArray<SDLSoftButton *> *softButtons;
+@property (strong, nonatomic, nullable) NSMutableArray<SDLSoftButton *> *softButtons;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLUpdateTurnList.m b/SmartDeviceLink/SDLUpdateTurnList.m
index 97b4942e0..59b332505 100644
--- a/SmartDeviceLink/SDLUpdateTurnList.m
+++ b/SmartDeviceLink/SDLUpdateTurnList.m
@@ -9,6 +9,8 @@
 #import "SDLSoftButton.h"
 #import "SDLTurn.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLUpdateTurnList
 
 - (instancetype)init {
@@ -17,7 +19,7 @@
     return self;
 }
 
-- (instancetype)initWithTurnList:(NSArray<SDLTurn *> *)turnList softButtons:(NSArray<SDLSoftButton *> *)softButtons {
+- (instancetype)initWithTurnList:(nullable NSArray<SDLTurn *> *)turnList softButtons:(nullable NSArray<SDLSoftButton *> *)softButtons {
     self = [self init];
     if (!self) {
         return nil;
@@ -29,20 +31,22 @@
     return self;
 }
 
-- (void)setTurnList:(NSMutableArray<SDLTurn *> *)turnList {
+- (void)setTurnList:(nullable NSMutableArray<SDLTurn *> *)turnList {
     [parameters sdl_setObject:turnList forName:SDLNameTurnList];
 }
 
-- (NSMutableArray<SDLTurn *> *)turnList {
+- (nullable NSMutableArray<SDLTurn *> *)turnList {
     return [parameters sdl_objectsForName:SDLNameTurnList ofClass:SDLTurn.class];
 }
 
-- (void)setSoftButtons:(NSMutableArray<SDLSoftButton *> *)softButtons {
+- (void)setSoftButtons:(nullable NSMutableArray<SDLSoftButton *> *)softButtons {
     [parameters sdl_setObject:softButtons forName:SDLNameSoftButtons];
 }
 
-- (NSMutableArray<SDLSoftButton *> *)softButtons {
+- (nullable NSMutableArray<SDLSoftButton *> *)softButtons {
     return [parameters sdl_objectsForName:SDLNameSoftButtons ofClass:SDLSoftButton.class];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLUpdateTurnListResponse.h b/SmartDeviceLink/SDLUpdateTurnListResponse.h
index ab2d87231..31ba28df5 100644
--- a/SmartDeviceLink/SDLUpdateTurnListResponse.h
+++ b/SmartDeviceLink/SDLUpdateTurnListResponse.h
@@ -7,6 +7,11 @@
 /** SDLUpdateTurnListResponse is sent, when SDLUpdateTurnList has been called.
  * Since<b>SmartDeviceLink 2.0</b>
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLUpdateTurnListResponse : SDLRPCResponse
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLUpdateTurnListResponse.m b/SmartDeviceLink/SDLUpdateTurnListResponse.m
index 584d3105a..d77ded773 100644
--- a/SmartDeviceLink/SDLUpdateTurnListResponse.m
+++ b/SmartDeviceLink/SDLUpdateTurnListResponse.m
@@ -7,6 +7,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLUpdateTurnListResponse
 
 - (instancetype)init {
@@ -16,3 +18,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLUploadFileOperation.m b/SmartDeviceLink/SDLUploadFileOperation.m
index 313ece825..aaba69fc0 100644
--- a/SmartDeviceLink/SDLUploadFileOperation.m
+++ b/SmartDeviceLink/SDLUploadFileOperation.m
@@ -52,7 +52,7 @@ NS_ASSUME_NONNULL_BEGIN
 - (void)start {
     [super start];
 
-    [self sdl_sendPutFiles:[self.class sdl_splitFile:self.fileWrapper.file mtuSize:[SDLGlobals globals].maxMTUSize] withCompletion:self.fileWrapper.completionHandler];
+    [self sdl_sendPutFiles:[self.class sdl_splitFile:self.fileWrapper.file mtuSize:[SDLGlobals sharedGlobals].maxMTUSize] withCompletion:self.fileWrapper.completionHandler];
 }
 
 - (void)sdl_sendPutFiles:(NSArray<SDLPutFile *> *)putFiles withCompletion:(SDLFileManagerUploadCompletionHandler)completion {
diff --git a/SmartDeviceLink/SDLV1ProtocolHeader.h b/SmartDeviceLink/SDLV1ProtocolHeader.h
index b7fa454f2..ecd5e258e 100644
--- a/SmartDeviceLink/SDLV1ProtocolHeader.h
+++ b/SmartDeviceLink/SDLV1ProtocolHeader.h
@@ -4,6 +4,8 @@
 
 #import "SDLProtocolHeader.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLV1ProtocolHeader : SDLProtocolHeader
 
 - (instancetype)init;
@@ -12,3 +14,5 @@
 - (NSString *)description;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLV1ProtocolHeader.m b/SmartDeviceLink/SDLV1ProtocolHeader.m
index d716c0c98..1de39fb29 100644
--- a/SmartDeviceLink/SDLV1ProtocolHeader.m
+++ b/SmartDeviceLink/SDLV1ProtocolHeader.m
@@ -6,6 +6,8 @@
 
 const int V1PROTOCOL_HEADERSIZE = 8;
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLV1ProtocolHeader
 
 - (instancetype)init {
@@ -39,7 +41,7 @@ const int V1PROTOCOL_HEADERSIZE = 8;
     return dataOut;
 }
 
-- (id)copyWithZone:(NSZone *)zone {
+- (id)copyWithZone:(nullable NSZone *)zone {
     SDLV1ProtocolHeader *newHeader = [[SDLV1ProtocolHeader allocWithZone:zone] init];
     newHeader.encrypted = self.encrypted;
     newHeader.frameType = self.frameType;
@@ -82,3 +84,5 @@ const int V1PROTOCOL_HEADERSIZE = 8;
 
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLV1ProtocolMessage.h b/SmartDeviceLink/SDLV1ProtocolMessage.h
index fb39fdf44..71903a5d0 100644
--- a/SmartDeviceLink/SDLV1ProtocolMessage.h
+++ b/SmartDeviceLink/SDLV1ProtocolMessage.h
@@ -5,10 +5,13 @@
 
 @class SDLProtocolHeader;
 
+NS_ASSUME_NONNULL_BEGIN
 
 @interface SDLV1ProtocolMessage : SDLProtocolMessage
 
-- (instancetype)initWithHeader:(SDLProtocolHeader *)header andPayload:(NSData *)payload;
-- (NSDictionary<NSString *, id> *)rpcDictionary;
+- (instancetype)initWithHeader:(SDLProtocolHeader *)header andPayload:(nullable NSData *)payload;
+- (nullable NSDictionary<NSString *, id> *)rpcDictionary;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLV1ProtocolMessage.m b/SmartDeviceLink/SDLV1ProtocolMessage.m
index 049e9ff7c..89ef946b9 100644
--- a/SmartDeviceLink/SDLV1ProtocolMessage.m
+++ b/SmartDeviceLink/SDLV1ProtocolMessage.m
@@ -5,9 +5,11 @@
 #import "SDLDebugTool.h"
 #import "SDLProtocolHeader.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLV1ProtocolMessage
 
-- (instancetype)initWithHeader:(SDLProtocolHeader *)header andPayload:(NSData *)payload {
+- (instancetype)initWithHeader:(SDLProtocolHeader *)header andPayload:(nullable NSData *)payload {
     if (self = [self init]) {
         self.header = header;
         self.payload = payload;
@@ -15,7 +17,7 @@
     return self;
 }
 
-- (NSDictionary<NSString *, id> *)rpcDictionary {
+- (nullable NSDictionary<NSString *, id> *)rpcDictionary {
     if (self.payload.length == 0) {
         return nil;
     }
@@ -31,3 +33,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLV2ProtocolHeader.h b/SmartDeviceLink/SDLV2ProtocolHeader.h
index c7a0d4272..bb93768bb 100644
--- a/SmartDeviceLink/SDLV2ProtocolHeader.h
+++ b/SmartDeviceLink/SDLV2ProtocolHeader.h
@@ -4,9 +4,11 @@
 
 #import "SDLProtocolHeader.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLV2ProtocolHeader : SDLProtocolHeader
 
-@property (assign) UInt32 messageID;
+@property (assign, nonatomic) UInt32 messageID;
 
 - (instancetype)init;
 - (instancetype)initWithVersion:(UInt8)version;
@@ -15,3 +17,5 @@
 - (NSString *)description;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLV2ProtocolMessage.h b/SmartDeviceLink/SDLV2ProtocolMessage.h
index 2cb6136ca..0c1cc065a 100644
--- a/SmartDeviceLink/SDLV2ProtocolMessage.h
+++ b/SmartDeviceLink/SDLV2ProtocolMessage.h
@@ -6,10 +6,13 @@
 
 @class SDLProtocolHeader;
 
+NS_ASSUME_NONNULL_BEGIN
 
 @interface SDLV2ProtocolMessage : SDLProtocolMessage
 
-- (instancetype)initWithHeader:(SDLProtocolHeader *)header andPayload:(NSData *)payload;
-- (NSDictionary<NSString *, id> *)rpcDictionary;
+- (instancetype)initWithHeader:(SDLProtocolHeader *)header andPayload:(nullable NSData *)payload;
+- (nullable NSDictionary<NSString *, id> *)rpcDictionary;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLV2ProtocolMessage.m b/SmartDeviceLink/SDLV2ProtocolMessage.m
index 84b3ec9be..8fb60f0e1 100644
--- a/SmartDeviceLink/SDLV2ProtocolMessage.m
+++ b/SmartDeviceLink/SDLV2ProtocolMessage.m
@@ -7,10 +7,11 @@
 #import "SDLProtocolHeader.h"
 #import "SDLRPCPayload.h"
 
+NS_ASSUME_NONNULL_BEGIN
 
 @implementation SDLV2ProtocolMessage
 
-- (instancetype)initWithHeader:(SDLProtocolHeader *)header andPayload:(NSData *)payload {
+- (instancetype)initWithHeader:(SDLProtocolHeader *)header andPayload:(nullable NSData *)payload {
     if (self = [self init]) {
         self.header = header;
         self.payload = payload;
@@ -19,7 +20,7 @@
 }
 
 // Convert RPC payload to dictionary (for consumption by RPC layer)
-- (NSDictionary<NSString *, id> *)rpcDictionary {
+- (nullable NSDictionary<NSString *, id> *)rpcDictionary {
     // Only applicable to RPCs
     if ((self.header.serviceType != SDLServiceType_RPC) && (self.header.serviceType != SDLServiceType_BulkData)) {
         return nil;
@@ -60,3 +61,5 @@
     return rpcMessageAsDictionary;
 }
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLVehicleDataResult.h b/SmartDeviceLink/SDLVehicleDataResult.h
index b586542d6..d0bbf59cb 100644
--- a/SmartDeviceLink/SDLVehicleDataResult.h
+++ b/SmartDeviceLink/SDLVehicleDataResult.h
@@ -6,9 +6,13 @@
 #import "SDLVehicleDataType.h"
 #import "SDLVehicleDataResultCode.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLVehicleDataResult : SDLRPCStruct
 
-@property (strong) SDLVehicleDataType dataType;
-@property (strong) SDLVehicleDataResultCode resultCode;
+@property (strong, nonatomic) SDLVehicleDataType dataType;
+@property (strong, nonatomic) SDLVehicleDataResultCode resultCode;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLVehicleDataResult.m b/SmartDeviceLink/SDLVehicleDataResult.m
index 60ed41805..3f4585076 100644
--- a/SmartDeviceLink/SDLVehicleDataResult.m
+++ b/SmartDeviceLink/SDLVehicleDataResult.m
@@ -6,6 +6,8 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLVehicleDataResult
 
 - (void)setDataType:(SDLVehicleDataType)dataType {
@@ -25,3 +27,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLVehicleType.h b/SmartDeviceLink/SDLVehicleType.h
index aceb40b72..4d7164bb4 100644
--- a/SmartDeviceLink/SDLVehicleType.h
+++ b/SmartDeviceLink/SDLVehicleType.h
@@ -9,6 +9,9 @@
  *
  * @since SDL 2.0
  */
+
+NS_ASSUME_NONNULL_BEGIN
+
 @interface SDLVehicleType : SDLRPCStruct
 
 /**
@@ -18,7 +21,7 @@
  *
  * Optional, Max String length 500 chars
  */
-@property (strong) NSString *make;
+@property (strong, nonatomic, nullable) NSString *make;
 
 /**
  * @abstract The model of the vehicle
@@ -27,7 +30,7 @@
  *
  * Optional, Max String length 500 chars
  */
-@property (strong) NSString *model;
+@property (strong, nonatomic, nullable) NSString *model;
 
 /**
  * @abstract The model year of the vehicle
@@ -36,7 +39,7 @@
  *
  * Optional, Max String length 500 chars
  */
-@property (strong) NSString *modelYear;
+@property (strong, nonatomic, nullable) NSString *modelYear;
 
 /**
  * @abstract The trim of the vehicle
@@ -45,6 +48,8 @@
  *
  * Optional, Max String length 500 chars
  */
-@property (strong) NSString *trim;
+@property (strong, nonatomic, nullable) NSString *trim;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLVehicleType.m b/SmartDeviceLink/SDLVehicleType.m
index b9241cab6..73e98aa20 100644
--- a/SmartDeviceLink/SDLVehicleType.m
+++ b/SmartDeviceLink/SDLVehicleType.m
@@ -7,38 +7,42 @@
 #import "NSMutableDictionary+Store.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLVehicleType
 
-- (void)setMake:(NSString *)make {
+- (void)setMake:(nullable NSString *)make {
     [store sdl_setObject:make forName:SDLNameMake];
 }
 
-- (NSString *)make {
+- (nullable NSString *)make {
     return [store sdl_objectForName:SDLNameMake];
 }
 
-- (void)setModel:(NSString *)model {
+- (void)setModel:(nullable NSString *)model {
     [store sdl_setObject:model forName:SDLNameModel];
 }
 
-- (NSString *)model {
+- (nullable NSString *)model {
     return [store sdl_objectForName:SDLNameModel];
 }
 
-- (void)setModelYear:(NSString *)modelYear {
+- (void)setModelYear:(nullable NSString *)modelYear {
     [store sdl_setObject:modelYear forName:SDLNameModelYear];
 }
 
-- (NSString *)modelYear {
+- (nullable NSString *)modelYear {
     return [store sdl_objectForName:SDLNameModelYear];
 }
 
-- (void)setTrim:(NSString *)trim {
+- (void)setTrim:(nullable NSString *)trim {
     [store sdl_setObject:trim forName:SDLNameTrim];
 }
 
-- (NSString *)trim {
+- (nullable NSString *)trim {
     return [store sdl_objectForName:SDLNameTrim];
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLVrHelpItem.h b/SmartDeviceLink/SDLVrHelpItem.h
index ba81745ad..e460538ac 100644
--- a/SmartDeviceLink/SDLVrHelpItem.h
+++ b/SmartDeviceLink/SDLVrHelpItem.h
@@ -5,15 +5,18 @@
 
 @class SDLImage;
 
+NS_ASSUME_NONNULL_BEGIN
 
 @interface SDLVRHelpItem : SDLRPCStruct
 
-- (instancetype)initWithText:(NSString *)text image:(SDLImage *)image;
+- (instancetype)initWithText:(NSString *)text image:(nullable SDLImage *)image;
 
-- (instancetype)initWithText:(NSString *)text image:(SDLImage *)image position:(UInt8)position;
+- (instancetype)initWithText:(NSString *)text image:(nullable SDLImage *)image position:(UInt8)position;
 
-@property (strong) NSString *text;
-@property (strong) SDLImage *image;
-@property (strong) NSNumber<SDLInt> *position;
+@property (strong, nonatomic) NSString *text;
+@property (strong, nonatomic, nullable) SDLImage *image;
+@property (strong, nonatomic) NSNumber<SDLInt> *position;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLink/SDLVrHelpItem.m b/SmartDeviceLink/SDLVrHelpItem.m
index d85a31a67..7a8b1d1e5 100644
--- a/SmartDeviceLink/SDLVrHelpItem.m
+++ b/SmartDeviceLink/SDLVrHelpItem.m
@@ -8,9 +8,11 @@
 #import "SDLImage.h"
 #import "SDLNames.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation SDLVRHelpItem
 
-- (instancetype)initWithText:(NSString *)text image:(SDLImage *)image position:(UInt8)position {
+- (instancetype)initWithText:(NSString *)text image:(nullable SDLImage *)image position:(UInt8)position {
     self = [self initWithText:text image:image];
     if (!self) {
         return nil;
@@ -21,7 +23,7 @@
     return self;
 }
 
-- (instancetype)initWithText:(NSString *)text image:(SDLImage *)image {
+- (instancetype)initWithText:(NSString *)text image:(nullable SDLImage *)image {
     self = [self init];
     if (!self) {
         return nil;
@@ -41,11 +43,11 @@
     return [store sdl_objectForName:SDLNameText];
 }
 
-- (void)setImage:(SDLImage *)image {
+- (void)setImage:(nullable SDLImage *)image {
     [store sdl_setObject:image forName:SDLNameImage];
 }
 
-- (SDLImage *)image {
+- (nullable SDLImage *)image {
     return [store sdl_objectForName:SDLNameImage ofClass:SDLImage.class];
 }
 
@@ -58,3 +60,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/SmartDeviceLinkTests/DevAPISpecs/SDLResponseDispatcherSpec.m b/SmartDeviceLinkTests/DevAPISpecs/SDLResponseDispatcherSpec.m
index e91fc6c35..3d5d2ef76 100644
--- a/SmartDeviceLinkTests/DevAPISpecs/SDLResponseDispatcherSpec.m
+++ b/SmartDeviceLinkTests/DevAPISpecs/SDLResponseDispatcherSpec.m
@@ -194,7 +194,10 @@ describe(@"a response dispatcher", ^{
             });
             
             it(@"should throw an exception if there's no button id", ^{
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wnonnull"
                 testSoftButton1.softButtonID = nil;
+#pragma clang diagnostic pop
                 testShow.softButtons = [@[testSoftButton1] mutableCopy];
                 
                 expectAction(^{ [testDispatcher storeRequest:testShow handler:nil]; }).to(raiseException().named(@"MissingIdException"));
@@ -238,8 +241,11 @@ describe(@"a response dispatcher", ^{
             });
             
             it(@"should throw an exception if there's no command id", ^{
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wnonnull"
                 testAddCommand.cmdID = nil;
                 
+#pragma clang diagnostic pop
                 expectAction(^{ [testDispatcher storeRequest:testAddCommand handler:nil]; }).to(raiseException().named(@"MissingIdException"));
             });
             
@@ -348,7 +354,10 @@ describe(@"a response dispatcher", ^{
             });
             
             it(@"should throw an exception if there's no button name", ^{
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wnonnull"
                 testSubscribeButton.buttonName = nil;
+#pragma clang diagnostic pop
                 
                 expectAction(^{ [testDispatcher storeRequest:testSubscribeButton handler:nil]; }).to(raiseException().named(@"MissingIdException"));
             });
@@ -525,7 +534,10 @@ describe(@"a response dispatcher", ^{
             });
             
             it(@"should throw an exception if there's no button id", ^{
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wnonnull"
                 testSoftButton1.softButtonID = nil;
+#pragma clang diagnostic pop
                 testAlert.softButtons = [@[testSoftButton1] mutableCopy];
                 
                 expectAction(^{ [testDispatcher storeRequest:testAlert handler:nil]; }).to(raiseException().named(@"MissingIdException"));
@@ -627,7 +639,10 @@ describe(@"a response dispatcher", ^{
             });
             
             it(@"should throw an exception if there's no button id", ^{
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wnonnull"
                 testSoftButton1.softButtonID = nil;
+#pragma clang diagnostic pop
                 testScrollableMessage.softButtons = [@[testSoftButton1] mutableCopy];
                 
                 expectAction(^{ [testDispatcher storeRequest:testScrollableMessage handler:nil]; }).to(raiseException().named(@"MissingIdException"));
diff --git a/SmartDeviceLinkTests/DevAPISpecs/SDLUploadFileOperationSpec.m b/SmartDeviceLinkTests/DevAPISpecs/SDLUploadFileOperationSpec.m
index 13ee3245d..a1bbc6baf 100644
--- a/SmartDeviceLinkTests/DevAPISpecs/SDLUploadFileOperationSpec.m
+++ b/SmartDeviceLinkTests/DevAPISpecs/SDLUploadFileOperationSpec.m
@@ -28,7 +28,7 @@ describe(@"Upload File Operation", ^{
     
     beforeEach(^{
         // Set the head unit size small so we have a low MTU size
-        [SDLGlobals globals].maxHeadUnitVersion = 2;
+        [SDLGlobals sharedGlobals].maxHeadUnitVersion = 2;
     });
     
     context(@"running a small file operation", ^{
@@ -145,13 +145,13 @@ describe(@"Upload File Operation", ^{
             SDLPutFile *firstPutFile = putFiles.firstObject;
             
             // First putfile
-            expect(firstPutFile.bulkData).to(equal([testFileData subdataWithRange:NSMakeRange(0, [SDLGlobals globals].maxMTUSize)]));
+            expect(firstPutFile.bulkData).to(equal([testFileData subdataWithRange:NSMakeRange(0, [SDLGlobals sharedGlobals].maxMTUSize)]));
             expect(firstPutFile.length).to(equal(@(testFileData.length)));
             expect(firstPutFile.offset).to(equal(@0));
             expect(firstPutFile.persistentFile).to(equal(@NO));
             expect(firstPutFile.syncFileName).to(equal(testFileName));
             
-            NSUInteger numberOfPutFiles = (((testFileData.length - 1) / [SDLGlobals globals].maxMTUSize) + 1);
+            NSUInteger numberOfPutFiles = (((testFileData.length - 1) / [SDLGlobals sharedGlobals].maxMTUSize) + 1);
             expect(@(putFiles.count)).to(equal(@(numberOfPutFiles)));
         });
     });
diff --git a/SmartDeviceLink_Example/Classes/ProxyManager.m b/SmartDeviceLink_Example/Classes/ProxyManager.m
index 4a4833808..17fcc1687 100644
--- a/SmartDeviceLink_Example/Classes/ProxyManager.m
+++ b/SmartDeviceLink_Example/Classes/ProxyManager.m
@@ -111,7 +111,7 @@ NS_ASSUME_NONNULL_BEGIN
 }
 
 - (void)showInitialData {
-    if ((self.initialShowState != SDLHMIInitialShowStateDataAvailable) || [self.sdlManager.hmiLevel isEqualToString:SDLHMILevelFull]) {
+    if ((self.initialShowState != SDLHMIInitialShowStateDataAvailable) || ![self.sdlManager.hmiLevel isEqualToString:SDLHMILevelFull]) {
         return;
     }