RE: Changes to Content Negotiation, Entity Tags, and If-*

>----------
>From: 	Daniel DuBois[SMTP:dan@spyglass.com]
>Sent: 	Tuesday, May 28, 1996 9:40 AM
>To: 	http-wg%cuckoo.hpl.hp.com@hplb.hpl.hp.com
>Cc: 	fielding@avron.ICS.UCI.EDU
>Subject: 	Re: Changes to Content Negotiation, Entity Tags, and If-*
>
>>subgroup's hypermail archive.  The only difference is that I require
>>Vary to be sent even when Alternates is present, since that is the only
>
>This is enough of a difference to concern me.  I have not yet seen a
>convincing series of examples that demonstrate a set of rules by which
>all
>parties can logically behave when presented with both a Vary header and
>an
>Alternates header in a response.
>
>If I as an origin server serve different responses based on the
>strlen() of
>the Accept: header, I would add "Vary: Accept".  That's a different
>beast
>than adding "Vary: Accept" to a transparently negotiated response.  You
>might be able to come up with a clear, air-tight description of
>Alternates
>that 'frees up' some of the constraints normally placed on a recipient
>by
>the presence of a Vary: header, but it has yet to be proven to me.

It seems pretty simple to me: if both Vary: and Alternates: were present
in a response, then a recipient should get correct behavior if it obeyed
either one and ignored the other.

Paul