http://www.rfc-editor.org/rfc/rfc4198.txt
RFC 4198: A Uniform Resource Name (URN) Namespace for Federated Content, D. Tessman2005-11-01T23:00:00-00:00This document describes a URN (Uniform Resource Name) namespace for identifying content resources within federated content collections. A federated content collection often does not have a strong centralized authority but relies upon shared naming, metadata, and access conventions to provide interoperability among its members. This memo provides information for the Internet community.