410 Gone

   The requested resource is no longer available at the server and no
   forwarding address is known. This condition is expected to be
   considered permanent. Clients with link editing capabilities SHOULD
   delete references to the Request-URI after user approval. If the
   server does not know, or has no facility to determine, whether or not
   the condition is permanent, the status code 404 (Not Found) SHOULD be
   used instead. This response is cacheable unless indicated otherwise.

   The 410 response is primarily intended to assist the task of web
   maintenance by notifying the recipient that the resource is
   intentionally unavailable and that the server owners desire that
   remote links to that resource be removed. Such an event is common for
   limited-time, promotional services and for resources belonging to
   individuals no longer working at the server's site. It is not
   necessary to mark all permanently unavailable resources as "gone" or
   to keep the mark for any length of time -- that is left to the
   discretion of the server owner.