Quote:
If the mandatory request has been forwarded by an HTTP/1.0
intermediary proxy then this is indicated either directly in the
Request-Line or by the presence of an HTTP/1.1 Via header field. In
this case, the server MUST include an Expires header field with a
date equal to or earlier than the value of the Date header field (see
section 9 for a discussion on caching considerations):
HTTP/1.1 200 OK
Date: Sun, 25 Oct 1998 08:12:31 GMT
Expires: Sun, 25 Oct 1998 08:12:31 GMT
Ext:
Cache-Control: no-cache="Ext", max-age=3600
...
Look at that! Look at that! Second line of the header!!! :)