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

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

HTTP/1.1 - June 1999

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

	▲	Jaxan 8 hours ago \| parent \| next [-]
		It (the http rfc) refers to other standards such as for URLs, and those did actually change (to include ipv6 and more internationalisation).
	▲	maxbond 9 hours ago \| parent \| prev [-]
		That's a tree, but the rest of that comment is the forest.