Proposed change to 10.4.7 (406 Not Acceptable)

In a recent phone conference, two changes to the 406 response text in
pre-04 section 10.4.7 were discussed.

The current text, annotated with the proposed changes:

>10.4.7 406 Not Acceptable
>The resource identified by the request is only capable of generating
>response entities which have content characteristics not acceptable
>according to the accept headers sent in the request.
>
>Unless it was a HEAD request, the response SHOULD include an entity
>containing a list of available entity characteristics and locations from
>which the user or user agent can choose the one most appropriate. 

To make it more clear that this list could also be a list of only one
entity, it is proposed to put parentheses around some plural s-es.  I
believe the changed text would be

 Unless it was a HEAD request, the response SHOULD include an entity
 containing a list of available entity characteristic(s) and
                                                     ^^^ 
 location(s) from which the user or user agent can choose the one most
         ^^^ 
 appropriate.

though I could be remembering the grammatical subtleties wrong.  

It is proposed that the same change is also made in section 10.3.1 (300
Multiple Choices).

>The
>entity format is specified by the media type given in the Content-Type
>header field. Depending upon the format and the capabilities of the user
>agent, selection of the most appropriate choice may be performed
>automatically.  However, this specification does not define any standard
>for such automatic selection.
>
>  Note: HTTP/1.1 servers are allowed to return responses which are
>  not acceptable according to the accept headers sent in the request.
>  In some cases, this may even be preferable to sending a 406
>  response.  User agents are encouraged to inspect the headers of an
>  incoming response to determine if it is acceptable.

To make it more clear what the user agent should do when it determines
that the incoming response is not acceptable, the addition of the
following sentence to the end of the note is proposed:

 If the response could be unacceptable, a user agent SHOULD
 temporarily stop receipt of more data and query the user for a
 decision on further actions.

It is believed that this sentence documents existing practice.

Koen.

Received on Thursday, 30 May 1996 16:25:02 UTC