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Re: Media types (are qualifiers lost?)

From: Chris Lilley <Chris.Lilley@sophia.inria.fr>
Date: Fri, 31 Oct 1997 00:21:00 +0100 (MET)
Message-Id: <9710310021.ZM1199@grommit.inria.fr>
To: Al Gilman <asgilman@access.digex.net>, w3c-css-wg@w3.org, w3c-wai-hc@w3.org (HC team)
On Oct 30,  6:10pm, Al Gilman wrote:

> In my reading of the October 24 draft for HTML 4 it does say that
> HTML user agents must be capable of doing the parsing that strips
> trailing qualifiers to isolate the base type and that they may
> ignore media type entries which do not match a predefined base
> type.

Yes. In other words, currently we only define media which are single
words, but browsers are hereby warned not to fall over if they come
across something more complicated. This is in an attempt to avoid
repeating the mess that happended with charsets in MIME (eg,
text/html;charset=iso-8859-1 being treated as an unknown type
since the parser wasn't expecting parameters).

> I do not believe that the present specification language requires
> a browser to ignore media subtypes or parameters, or that it
> requires a browser even to ignore off-the-wall media types

correct.

> As I read it, the whole point of the "future versions of HTML may
> define...  parametric" explanation is to say that browsers
> designed to this spec have to be compatible with media type
> indications that contain subtype or parameter qualifiers.

yes

> This spec doesn't require them to honor such qualifiers in any
> way.  But it doesn't stop them, either.  CSS2 or the Browser
> Guidelines could ask for specific functions relating to media
> type qualifiers and it would be entirely consistent with this
> specification language.

yes.

-- 
Chris Lilley, W3C                          [ http://www.w3.org/ ]
Graphics and Fonts Guy            The World Wide Web Consortium
http://www.w3.org/people/chris/              INRIA,  Projet W3C
chris@w3.org                       2004 Rt des Lucioles / BP 93
+33 (0)4 93 65 79 87       06902 Sophia Antipolis Cedex, France
Received on Thursday, 30 October 1997 18:21:42 UTC

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