Contradictory?

   5.  The user's server MUST also stamp the presence stanza of type
       "subscribe" with the user's bare JID (i.e., <user@example.com>)
       as the 'from' address (if the user provided a 'from' address set
       to the user's full JID, the server SHOULD remove the resource
       identifier).  If the contact is served by a different host than