proposed media type registration: application/voicexml+xml

[Martin Duerst]

At 19:15 03/12/18 +0100, Max Froumentin wrote:
>Linus Walleij <triad at df.lth.se> wrote:

> > OK so then I regard this as official W3.org policy on transport type.
>
>I expect that that policy would rather be set by the TAG. See:
>http://www.w3.org/2001/tag/2002/0129-mime
>
>"Thus there is no ambiguity when the charset is omitted, and the
>STRONGLY RECOMMENDED injunction [in RFC3023] to use the charset is
>misplaced for application/xml and for non-text "+xml"
>types.

I agree that we should change the 'strongly recommended' to a
more balanced wording and a more detailed discussion in
the upcomming RFC 3023 update.

I also just found out that there are apparently two findings
dealing with the above issue, the other one (still at draft
stage) at http://www.w3.org/2001/tag/doc/mime-respect-20031210.html
(diff at
http://www.w3.org/2001/tag/doc/mime-respect-20031210-diff.html).


>Consequently, for XML representations, server-side applications
>SHOULD only supply a charset header when there is complete certainty
>as to the encoding in use. Otherwise, an error will cause a perfectly
>usable representation to be rejected by an architecturally sound
>client."

I think that this is basically right, but highly overstated.
There are two points:

1) It implies that leaving off the charset parameter will always
    lead to perfectly correct documents.
    While there are certain cases where indeed leaving out the
    charset parameter will improve things, when the charset
    parameter is wrong, there are also cases where things will
    get worse, and there are cases where things are not affected.

2) The language used seems to be inappropriate for a specification,
    because specifications in general assume that people do what
    the spec says. If we would fill up our specs with notes saying
    that you shouldn't do this if you don't get it right, our specs
    would all be much longer and much more difficult to read.


In addition, note that the finding you cited continues as follows:

 >>>>>>>>
We recommend that section 7.1 of [RFC3023] be amended to something like the 
following:

     The use of the charset parameter, when the charset is reliably known 
and agrees with the encoding declaration, is RECOMMENDED, since this 
information can be used by non-XML processors to determine authoritatively 
the charset of the XML MIME entity.
 >>>>>>>>

So it does not look to me that the TAG is recommending to remove
the charset parameter from application/foo+xml registrations.


Regards,     Martin.