LC-1998: application/xhtml+xml MIME type

(Trying to get the LC responses I am responsible for finished up-this is
the first of several.)

Comment:

-	the "application/xhtml+xml" MIME type should be the basis for an
heuristics that informs transcoders that no transcoding must be applied.
The rationale for this is obvious: this MIME type is being used for
mobile content virtually exclusively these days


Proposed Response:

This may be true (I'm not sure), but it is at odds with the "XHTML Media
Types" W3C Note (http://www.w3.org/TR/xhtml-media-types/) which
recommends that the application/xhtml+xml media type should be used for
all XHTML documents, not just mobile ones.  This media type could be
used a clue that the content is designed for mobile devices, but I don't
think it should be used as the only piece of information to decide
whether content is mobile or not.

I believe that we decided at some point to leave specific examples of
content types out of the list of heuristics in section 4.3.6 because it
was difficult to come up with a list of content types that were
specifically mobile.

As a side note, it appears most if not all of the content on the w3.org
is returned using the application/xhtml+xml content type.  These pages
would all be recognized as mobile if we recommended this heuristic.
(And we all know that mobile WWW users spend large amounts of time
reading W3C documents.)


Sean