Questions tagged
A RFC entitled "Uniform Resource Identifier (URI): Generic Syntax"

See rfc for more details on RFC

RFC 3986 was released in January 2005.

It supersedes RFC 2732, RFC 2396 and RFC 1808.

Note however the current URL Standard at has among its goals:

Align RFC 3986 and RFC 3987 with contemporary implementations and obsolete them in the process. (E.g., spaces, other "illegal" code points, query encoding, equality, canonicalization, are all concepts not entirely shared, or defined.)