Re: Media types

On 17 Jan 2002, Simon St.Laurent wrote:

> 
> Sorry to come to this discussion late. (Those reading this on
> ietf-xml-mime may want to visit
> http://lists.w3.org/Archives/Public/www-tag/2002Jan/index.html and read
> the Media Types thread.)
> 
> On Thu, 2002-01-17 at 13:41, Mark Baker wrote:
> > >[Tim Bray]
> > > Hm... you're creeping in the direction of deprecating media type
> > > MIME headers in the case where the resource body is XML.
> > 
> > Not deprecating, just creating a parallel alternative.  But if it's
> > done well, it could become a 90+% solution.
> > 
> > >  To start
> > > with, should such a discussion happen at least partly over in the
> > > IETF?
> > 
> > For sure.  This won't happen without the IETF.
> 

For me, the main points (which simon has nicely captured) for XML and
MIME are::
  * using URIs to reference vocabulary definitions
  * XML documents can reference multiple vocabulary definition
  * The mime mechanism can capture only one of these vocabularies

(note how this dances carefully away from the word 'type' ;-) )

MIME really doesn't give you a nice way of defining multipe properties for
a single resource, other than the media features extension described
in RFC 2912. Using this extension (Designed for a different purpose, BTW)
you could write something like:

Content-Type: text/xml;
Content-features:
        (& (primary-namespace="uri1")
           (secondary-namespace="uri2")
           ...
        )

The question then is -- does that really give you anything particularly
useful over text/xml+whatever?  Once I started to think through some
uses, I honestly couldn't think of a compelling advantage ...

Ian