Section 1.1.1 of RFC 3986 defines URI syntax as "a federated and
extensible naming system wherein each scheme's specification may
further restrict the syntax and semantics of identifiers using that
scheme." In other words, the structure of a URI is defined by its
scheme. While it is common for schemes to further delegate their
substructure to the URI's owner, publishing independent standards
that mandate particular forms of substructure in URIs is often
problematic.
This document provides guidance on the specification of URI
substructure in standards.
This document obsoletes RFC 7320 and updates RFC 3986.