http://www.rfc-editor.org/rfc/rfc4246.txt
RFC 4246: International Standard Audiovisual Number (ISAN) URN Definition, M. Dolan2006-02-01T23:00:00-00:00The International Standard Audiovisual Number (ISAN) is a standard numbering system for the unique and international identification of audiovisual works. This document is the definition of the formal Uniform Resource Name (URN) Namespace Identifier (NID) for ISAN. This memo provides information for the Internet community.