Long: http0.9
Tags: Versions
Protocols: HTTP
Help: Allow HTTP 0.9 responses
Category: http
Example: --http0.9 $URL
Added: 7.64.0
See-also: http1.1 http2 http3
---
Tells curl to be fine with HTTP version 0.9 response.

HTTP/0.9 is a completely headerless response and therefore you can also
connect with this to non-HTTP servers and still get a response since curl will
simply transparently downgrade - if allowed.

Since curl 7.66.0, HTTP/0.9 is disabled by default.