If-Modified-Since enhancement

Ari Luotonen (luotonen@ptsun00.cern.ch)
Mon, 21 Mar 1994 21:21:04 --100


Since nobody objected, and some gave me feedback saying it was
a good idea, the HTTP spec now says:

NOT MODIFIED 304

If the client has done a conditional GET and access is allowed, but
the document has not been modified since the date and time specified
in If-Modified-Since field, server responds with 304 status code, and
does not send the document back to the client.

NEW: Response headers are as if the client had originally sent a HEAD request.
NEW: This way the server can upload a new expiry date and other necessary
NEW: metainformation to the requesting client (often a caching proxy).

This is to allow fast update of caches.


-- Cheers, Ari --