Abstract This document defines two new HTTP headers "Content-Profile" and "Accept-Profile" that enable User Agents and hosts to indicate and negotiate the profile used for representing a specific resource. In this context, a profile is a description of the structural and/or semantic constraints of a group of documents in addition to the syntactical interpretation provided by more generic MIME types. Examples of profiles include Dublin Core Application Profiles, XML Schemata, and RDF Shape Expressions. This document further defines and registers the "profile" parameter for the HTTP "Link" header and suggests a best practice for the use of the new headers together with the "Link" header for the purposes of performing content negotiation and pointing clients to alternate representations.