1 files changed, 58 insertions, 3 deletions
diff --git a/django/contrib/postgres/fields/citext.py b/django/contrib/postgres/fields/citext.py
index 2b943614d2..2dac2577d1 100644
--- a/django/contrib/postgres/fields/citext.py
+++ b/django/contrib/postgres/fields/citext.py
@@ -1,9 +1,22 @@
+import warnings
+
 from django.db.models import CharField, EmailField, TextField
+from django.test.utils import ignore_warnings
+from django.utils.deprecation import RemovedInDjango51Warning
 
 __all__ = ["CICharField", "CIEmailField", "CIText", "CITextField"]
 
 
+# RemovedInDjango51Warning.
 class CIText:
+    def __init__(self, *args, **kwargs):
+        warnings.warn(
+            "django.contrib.postgres.fields.CIText mixin is deprecated.",
+            RemovedInDjango51Warning,
+            stacklevel=2,
+        )
+        super().__init__(*args, **kwargs)
+
     def get_internal_type(self):
         return "CI" + super().get_internal_type()
 
@@ -12,12 +25,54 @@ class CIText:
 
 
 class CICharField(CIText, CharField):
-    pass
+    system_check_deprecated_details = {
+        "msg": (
+            "django.contrib.postgres.fields.CICharField is deprecated. Support for it "
+            "(except in historical migrations) will be removed in Django 5.1."
+        ),
+        "hint": (
+            'Use CharField(db_collation="…") with a case-insensitive non-deterministic '
+            "collation instead."
+        ),
+        "id": "fields.W905",
+    }
+
+    def __init__(self, *args, **kwargs):
+        with ignore_warnings(category=RemovedInDjango51Warning):
+            super().__init__(*args, **kwargs)
 
 
 class CIEmailField(CIText, EmailField):
-    pass
+    system_check_deprecated_details = {
+        "msg": (
+            "django.contrib.postgres.fields.CIEmailField is deprecated. Support for it "
+            "(except in historical migrations) will be removed in Django 5.1."
+        ),
+        "hint": (
+            'Use EmailField(db_collation="…") with a case-insensitive '
+            "non-deterministic collation instead."
+        ),
+        "id": "fields.W906",
+    }
+
+    def __init__(self, *args, **kwargs):
+        with ignore_warnings(category=RemovedInDjango51Warning):
+            super().__init__(*args, **kwargs)
 
 
 class CITextField(CIText, TextField):
-    pass
+    system_check_deprecated_details = {
+        "msg": (
+            "django.contrib.postgres.fields.CITextField is deprecated. Support for it "
+            "(except in historical migrations) will be removed in Django 5.1."
+        ),
+        "hint": (
+            'Use TextField(db_collation="…") with a case-insensitive non-deterministic '
+            "collation instead."
+        ),
+        "id": "fields.W907",
+    }
+
+    def __init__(self, *args, **kwargs):
+        with ignore_warnings(category=RemovedInDjango51Warning):
+            super().__init__(*args, **kwargs)