https://datatracker.ietf.org/doc/draft-ietf-urnbis-rfc3406bis-urn-ns-reg/
draft-ietf-urnbis-rfc3406bis-urn-ns-reg-09 - Uniform Resource Name (URN) Namespace Definition...
This document supplements the Uniform Resource Name (URN) syntax specification by defining the concept of a URN namespace, as well as mechanisms for defining...