http://www.rfc-editor.org/rfc/rfc5829.txt
RFC 5829: Link Relation Types for Simple Version Navigation between Web Resources, A. Brown, G. Clemm, J. Reschke2010-04-01T23:00:00-00:00This specification defines a set of link relation types that may be used on Web resources for navigation between a resource and other resources related to version control, such as past versions and working copies. This document is not an Internet Standards Track specification; it is published for informational purposes.