Link: http://trac.tools.ietf.org/wg/httpbis/trac/ticket/110
Component: non-specific
A response can carry a representation/entity of the resource identified by the request-uri, but it can also carry an entity associated with a different resource, as per the Content-Location header, or it may even carry an "anonymous" representation that isn't associated with a URI (a.k.a. a "status message").
The rules for determining this should be clarified in the specification.
Depends on #69 to some degree. See also #22.