Re: HTTP HEAD requests for Last-Modified info

• From: Marc Salomon <marc@ckm.ucsf.edu>
• Date: Thu, 20 Jun 1996 14:12:46 -0700
• To: www-talk@w3.org
• Message-Id: <9606201412.ZM7538@home.ckm.ucsf.edu>

>|Caching is essential to HTTP scalability in the near-term.
|Actually, caching can work without Last-Modified, as long as the
|origin server sends Expires and an ETag.

Right.  But in the near term HTTP 1.0 caches and user agents won't understand
 Etag but do understand Expires and how to send an If-Modified-Since
conditional request.  On the other end, many resources served through HTTP 1.0
do not have an explicit Expires value.

"The more information a server can send with a resource to describe its
expiration characteristics, the better for caching" seems like a good rule of
thumb.

-marc

-- 

Received on Thursday, 20 June 1996 17:13:33 UTC