RE: [opendocument-users] Harmonization with IS 29500-3:2008 Marcup Compatibility and Extensibility

["Dennis E. Hamilton" <dennis.hamilton@acm.org>]

Paul,

I have been a big fan of the OOXML Markup Compatibility and Extensibility (MCE) specification since I saw its early form in drafts of what would become ECMA-376 (edition 1).   

Your recommendation has inspired me to review the current document (also available at http://www.ecma-international.org/publications/standards/Ecma-376.htm).

I think the IS 29500-3:2008 specification would do the job rather completely.  Relying on MCE is also in the spirit of ODF relying on existing standards where one is available. 

I'm not quite sure what to do with this.  It seems worth raising at the ODF TC to see if it is worthy of consideration for 1.2 or should be tabled to ODF-next.  

The fallback seems to be to leave Extended ODF Document, perhaps with tighter language around how non-understood elements and attributes are to be handled, until such time as MCE could be adopted.  

I don't see MCE availability as eliminating the Extended ODF Document conformance class.  On the contrary, any allowance of MCE elements and attributes might be limited to the Extended ODF Document conformance class when introduced.  I'm just guessing here.  The provisions for inter-version compatibility are worth considering at a fundamental (non-extension) conformance level.

 - Dennis

This message is my personal observation and any similarity to an official position of the ODF TC or of OASIS is purely coincidental.  Were there such an official position, there'd be provision of a link to the official minutes or other approved document where the official position is expressed.

Dennis E. Hamilton
------------------
NuovoDoc: Design for Document System Interoperability 
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FURTHER ANALYSIS

A. Non-Technical Considerations for Adopting IS 29500-3:2008 

   A.1 I am aware that there are those that will not find this specification acceptable under any conditions because of the feared prospect of a Microsoft intellectual-property dependency being submarined into the specification regardless of the various royalty-free arrangements that Microsoft has asserted, especially its Open Specification Promise.  

   A.2 The absence of indiscriminate/unrestricted sublicensing is also a barrier for some, as you know.  None of this bothers me, but for some it is a complete show-stopper.  (For that reason, whatever its foundation in reality, I suppose use of MCE should always be optional and always processable as if foreign elements and attributes.)

   A.3 There are important concerns for timing and process capability with regard to introducing something like this into ODF 1.2.  

   A.4 It is an interesting feature of the extended ODF Document provisions, such as they are at the moment, that the special MCE attributes could be introduced by implementations in a provisional way, since their being ignored would not make anything the worse for wear.  

   A.5 The opportunity of (A.4) does not extend to <mce:AlternateContent> elements, except for the case where an MCE-unaware consumer recognizes and processes a constituent of the AlternateContent that is not an MCE element and is understood by the that consumer.  My reading of MCE section 10.2.1 is that an MCE AlternateContent element can contain an MCE-ignored content element that would end up being processable by an MCE-unaware consumer depending on how it strips away the foreign MCE parts.  (This is a quasi-non-technical consideration that might provide an avenue for early experimentation in 1.2 implementations before the ODF markup specification catches up, if ever.)

B. Technical Considerations for Adopting IS 29500-3:2008

   B.1 MCE seems to cover all of the bases as far as being able to control adjustment between versions of ODF as well as deal with use of extensions and even the selective reliance on extensions and add ins depending on what is understood and supported by an implementation.  It is an elaborate arrangement, and also raises some interesting questions about how and whether MCE should be optional or mandatory with respect to ODF conformance targets.  (This is a quasi-technical consideration, as all conformance-related conditions are.)

   B.2 The normative dependencies in MCE section 3 would need to be reconciled with any ODF reliance on (versions of) the same standards.

   B.3 There are expectations concerning namespace versioning that the ODF specification would need to review and address in some manner (MCE section 9.1 at the end and section 11 on Namespace Subsumption) as part of the ODF specification, whether providing for subsumption or not.  

   B.4 There are many places in MCE Sections 10-12 where there must be reconciliation between MCE and what a markup specification (i.e., the ODF standard) says about processing of understood and non-understood elements and attributes.  The profiling of MCE for ODF must include what those reconciliations are.

   B.5 We need to deal with a typo in MCE section 10.1.3.2 where "ProcessAttributes" is used where "PreserveAttributes" is the only term possibly intended.

   B.5. MCE Section 11 on Namespace subsumption has implications for how alignment of the ODF markup specification with MCE is done.

   B.6. Because of the many other specifications that the ODF markup specification adopts by reference and modification, how MCE will or will not be supported in those ODF adaptations must be addressed as well.  This could be done as part of tightening the adaptation of other markups as parts of ODF markup.  It is probably important to do that.

-----Original Message-----
From: marbux [mailto:marbux@gmail.com] 
http://lists.oasis-open.org/archives/opendocument-users/200903/msg00020.html
Sent: Saturday, March 07, 2009 20:48
To: dennis.hamilton@acm.org
Cc: Alex Brown; ODF Users List
Subject: Re: [opendocument-users] RE: office-comment Frames / Information Loss (ODF all versions)

Re preservation and processing of unrecognized markup:

This is an area where some harmonization with ISO/IEC:29500-2008 might
be seriously considered. Part 3 -- Markup Compatibility and
Extensibility specifies a compatibility framework reliant on
compatibility and alternate content attributes.

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