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XMLP WG request for revision of uriMediaType-9 issue and related finding

From: David Orchard <dorchard@bea.com>
Date: Fri, 12 Dec 2003 14:17:51 -0800
To: <tag@w3.org>
Cc: <xml-dist-app@w3.org>
Message-ID: <014e01c3c0fd$c97f5510$6601a8c0@beasys.com>

Dear TAG,

On behalf of the XML Protocol working group, we would like to request a
revision of uriMediaType-9 [1] issue and the related finding [2], and that
this be prioritized sufficiently to enable a speedy resolution, preferably
by early January.  This issue is currently open and listed as being closed
after v1.0 Web Architecture document.  We observe that there have been
recent updates by IANA, particularly the provision of http uris for media
types [3] and urn URIs for IANA parameters such as media types in RFC 3553
[4].

By way of background, the XML Protocol Working group and the Web Services
Description Working Group have formed a task force to specify the
representation and descripion of binary content in SOAP.  There is a
requirement to be able to identify in the representation the media type of
the binary content.

We seem to have 3 major options available for identifying media types in
XML:
1) IANA media type tokens, ie xsi:mediaType="image/jpeg".
2) HTTP URIs, ie
xsi:mediaType="http://www.iana.org/assignments/media-types/image/jpeg"
3) URN URIs, ie xsi:mediaType="urn:ietf:param:contentType:image:jpeg"

We note that example #2: is not guaranteed to be dereferencable (the example
given is not dereferencable at the time of this writing); it is a
manufactured URI and we're not sure that it is valid; we're not sure about
the longevity of those URIs;  and we sense that option #2 is less preferred
by IETF than option #3.  We also note that option #1 appears to more
naturally fit with existing software that deals with media types.  A finding
that describes the benefits and costs of the approaches and helped us in our
decision would be appreciated.

We are not asking the question about the namespace name nor the local name
of the attribute, simply the content model of the attribute.  The use of
xsi: as the prefix is only to illustrate one possible namespace name that
could be created within the W3C.  A standardized namespace, type name and
attribute name might be useful to the larger community but we don't believe
that XMLP WG needs to solve that problem.  Though it closely examine any
solution should one emerge in a timely manner.

Cheers,
Dave

[1] http://www.w3.org/2001/tag/issues.html#uriMediaType-9
[2] http://www.w3.org/2001/tag/2002/01-uriMediaType-9
[3] http://www.iana.org/assignments/
[4] http://www.ietf.org/rfc/rfc3553.txt
Received on Friday, 12 December 2003 17:18:29 GMT

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