Multiprotocol Label Switching (MPLS) Label Switched Paths (LSPs) established using the Resource Reservation Protocol Traffic Engineering (RSVP-TE) extensions may be signaled with a set of LSP specific attributes. These attributes may be carried in both Path and Resv messages. This document specifies how LSP attributes are to be carried in RSVP Path and Resv messages using the Routing Backus-Naur Form, and clarifies related Resv message formats.