Re: Fwd:HTTP server driven content negotiation

From: Michael A. Dolan (
Date: Mon, Mar 08 1999

Message-Id: <>
Date: Mon, 08 Mar 1999 07:57:55 -0800
To: Henrik Frystyk Nielsen <>, Johan Hjelm <>, Philipp Hoschka <>,
From: "Michael A. Dolan" <>
Subject: Re: Fwd:HTTP server driven content negotiation


I understand.  My thinking was that one could use/invent Request fields
that might be useful.  For example:

	Vary X-profile1
	Vary Accept x-profiles/1

I've probably buggered the syntax up a little, but you get the idea...


At 09:44 AM 3/8/99 -0500, Henrik Frystyk Nielsen wrote:
>At 15:11 3/8/99 +0100, Johan Hjelm wrote:
>>>HTTP 1.1 has the Vary tag and the concept of server driven content
>>>negotiation.  However, I found the use of the Vary tag somewhat vague.
>>>Anyone have any experience with this tag?  Is there more info somewhere at
>>>W3C on this - from the HTTP 1.1 author perhaps?
>The vary header field is a mechanism for the origin server to tell a cache
>what it used in the request to generate that particular response. As this
>is not the case in a push situation, it really doesn't help that much.
>Henrik Frystyk Nielsen,
>World Wide Web Consortium
Michael A. Dolan, Representing DIRECTV,  (619)445-9070   
PO Box 1673 Alpine, CA 91903        FAX: (619)445-6122