Speaking for cern_httpd which is just a kind of client-server hybrid --
whatever works for both clients and servers will work for caching proxy.
> (BTW, as long as we're talking about cache servers, how do cache
> servers handle negotiation of Content-Type?)
Proxy becomes a client that can handle all the formats that the remote
client has Accept:ed, and presents them by wrapping them to MIME and
sending back.
-- Cheers, Ari --