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RE: Proposed resolution for issue 440

From: Dale Moberg <dmoberg@cyclonecommerce.com>
Date: Thu, 6 Nov 2003 09:16:39 -0700
Message-ID: <A1C7F8CC121B444CA879FB66B3268A1A03F6AF@usazscsmh1.cyclonecommerce.com>
To: "Martin Gudgin" <mgudgin@microsoft.com>, "Xml-Dist-App@W3. Org" <xml-dist-app@w3.org>


Even the HTTP flavor of MIME syntax allows any MIME entity to be
packaged up with other bodyparts. Prohibiting this compositional
functionality is in flagrant violation of MIME rules.

Even if we were to think of MTOM as akin to an encapsulation (such as
the MIME within BER of CMS), no prohibition on combination with
encapsulted MIME has any precedent in open internet standards.

Possibly since MTOM uses multipart/related, it would be possible to say,
that for this multipart/related usage, that every bodypart in the MTOM
multipart/related is referenced by exactly one xbinc:include. 

Assertions going that restriction would, however, violate well-entreched
older internet/web technology. No good technical reason has been given
for going that far. IMO arbitrary disruptions to established open
standards is generally a good thing to avoid, even when seeking the "one
ring to rule them all."

If the prohibition on combining with other parts is adopted, SOAP MTOM
should not be used in either SMTP, HTTP or HTTPS MIME transfer
situations IMO. 

You cannot build an applicability profile of a "CAN be combined with any
X" by saying "MUST NOT combined with any X other than these." So this is
not a profiling of a standard, but a violation of a standard. I don't
think you should go there. As indicated above, the infoset preoccupation
does not even require this convention.

Dale Moberg


The above pertains IMO to what Gudge stated here:

"On the call today we discussed issue 440[1] which asks 

1. 	whether MTOM packages can contain MIME body parts that are NOT
referenced by an xbinc:Include element
2.	whether a MIME body oart can be referenced by multiple
xbinc:Include elements

I took an action to propose a resolution to this issue, so here it is.

Proposed resolution:

Each MIME body part (except the root) MUST be referenced by exactly one
xbinc:Include element. Intermediaries are required to respect this rule.

Rationale:

Allowing MIME parts that are unreferenced breaks the infoset model.
Ensuring MIME parts are referenced exactly once simplifies
implementations.

Cheers

Gudge

[1] http://www.w3.org/2000/xp/Group/xmlp-issues.html#x440
"
Received on Thursday, 6 November 2003 11:19:26 GMT

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