[geysersam]

This is the HTTP/1.1 standard: https://datatracker.ietf.org/doc/html/rfc2616

Then there are also HTTP/2 and HTTP/3.

That's just HTTP, curl supports 27 other protocols.

[dist-epoch]

HTTP/1.1 - June 1999

It's not like the standard changed since curl was created

[Jaxan]

It (the http rfc) refers to other standards such as for URLs, and those did actually change (to include ipv6 and more internationalisation).

[maxbond]

That's a tree, but the rest of that comment is the forest.