http://www.rfc-editor.org/rfc/rfc4874.txt
RFC 4874: Exclude Routes - Extension to Resource ReserVation Protocol-Traffic Engineering (RSVP-TE), CY. Lee, A. Farrel, S. De Cnodder2007-04-01T23:00:00-00:00In some networks where precise explicit paths are not computed at the head end, it may be useful to specify and signal abstract nodes and resources that are to be explicitly excluded from routes. These exclusions may apply to the whole path, or to parts of a path between two abstract nodes specified in an explicit path. How Shared Risk Link Groups (SRLGs) can be excluded is also specified in this document. [STANDARDS-TRACK]