W3C home > Mailing lists > Public > w3c-dist-auth@w3.org > July to September 1998

etag in untagged production of If header

From: Jim Davis <jdavis@parc.xerox.com>
Date: Sat, 12 Sep 1998 11:14:40 PDT
Message-Id: <3.0.5.32.19980912111440.007d0a60@mailback.parc.xerox.com>
To: w3c-dist-auth@w3.org
The no-tagged production of an If header is to be applied to every resource
to which the method is applied.  This production can contain both state
tokens and etags.  I understand why the no-tagged production is useful when
it contains a state token.  Many distinct resources can be in the same
state.  I do not understand why this production can contain an etag.
Unlike a state token, an etag can match at most one resource, and the only
way a client could have an etag in the first place is by already knowing
the resource.  So it would always be possible for the client to use the
tagged production.

Can someone provide an example of when it would ever make sense to include
an etag in such a production?

The only reason I can think of is to allow the client to transmit slightly
fewer bytes on the wire.

I am not calling for any changes in the protocol or documentation, but
would like to know whether I missed something.

Jim





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Received on Saturday, 12 September 1998 14:15:26 GMT

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