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Re: CONTENT-ENCODING: FIXED revised proposed wording

From: Martin J. Duerst <mduerst@ifi.unizh.ch>
Date: Wed, 23 Jul 1997 11:58:07 +0200 (MET DST)
To: Jeffrey Mogul <mogul@pa.dec.com>
Cc: http-wg%cuckoo.hpl.hp.com@hplb.hpl.hp.com
Message-Id: <Pine.SUN.3.96.970723114235.245K-100000@enoshima>
On Tue, 22 Jul 1997, Jeffrey Mogul wrote:

> [OOPS.  My previous message was missing one very important sentence,
> regarding when "identity" content-codings are implicitly allowed.  -Jeff]

> (2) Replace section 14.3 (Accept-Encoding) entirely with
> 
>     14.3 Accept-Encoding 


>     A server tests whether a content-coding is acceptable, according
>     to an Accept-Encoding field, using these rules:
> 	(1) If the content-coding is one of the content-codings listed
> 	in the Accept-Encoding field, then it is acceptable. (Note that,
> 	as defined in section 3.9, a qvalue of 0 means "not acceptable".)
> 	(2) The special "*" symbol in an Accept-Encoding field matches
> 	any available content-coding.
> 	(3) If multiple content-codings are acceptable, then the
> 	acceptable content-coding with the highest non-zero qvalue is
> 	preferred.  
> 	(4) The "identity" content-coding is always acceptable, unless
> 	specifically refused because the Accept-Encoding field includes
> 	"identity;q=0", or because the field includes "*;q=0" and does
> 	not explictly include the "identity" content-coding.  If the
> 	Accept-Encoding field-value is empty, then only the "identity"
> 	encoding is acceptable.

A lot of what is written above turns up exactly the same in
Accept-Charset, Accept-Language, and so on. In many cases, there
is something special, but not too much. Is there a way to organize
the text different? This would hopefully a) save space, b) help
getting an overview, and c) make things more consistent.

For example, with respect to "*", the general description could
say that:

"*" in an accept field matches any value possible in that accept
field, including a default. A q-value given to "*" applies to all
values, including the default, but except those that are explicitly
present. An accept field may not allow "*", or may use a more
elaborate syntax for this functionality. Such cases are explicitly
mentionned in the description of the field itself.

Similar texts could explain the use of a default, the meaning of
q=0 (this seems already done to a certain extent), and so on.

For "Accept-Encoding", we would then just have to list the
possible values and identify the default.


Regards,	Martin.
Received on Wednesday, 23 July 1997 04:39:29 EDT

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