RFC 2616 also says "For definitive information on URL syntax and semantics, see "Uniform Resource Identifiers (URI): Generic Syntax and Semantics," RFC 2396" an

RFC 2616 also says "For definitive information on URL syntax and semantics, see "Uniform Resource Identifiers (URI): Generic Syntax and Semantics," RFC 2396" and it is frequently documented on the interwebs that HTTP uses the generic URI syntax. I'm not trying to suggest that the intent of the RFC was to allow <authority> where it says <host> in 3.2.2 but I can see how this wording might be confusing, especially when taken with historically observed UA behaviour.