New proposed dispositions extend progress in addressing all National Body comments, seek to document and resolve legacy issues – Nearly 2/3 of comments now reviewed
21 December 2007 - Ecma TC45 has been making continued progress on the comment review process, supporting the ISO/IEC DIS 29500 Project Editor’s mid-January deadline to deliver a comprehensive report of Ecma’s proposed dispositions.
Today’s batch of proposed dispositions brings the total number of items TC45 has responded to thus far to 2298, or 65.25% (nearly two thirds) of the 3,522 total comments received across all 87 voting countries.
As referenced in previous communication, this working group has been heavily focused on defining recommendations that are informed by National Body feedback and serve to make the Open XML standard better.
Significant changes being proposed with this new batch of dispositions are outlined below.
Treatment of dates and related calculations
a) Storing dates before 1900
ECMA-376 did not specify rules for calculating values using dates before 1900. Based on input from the National Bodies in 19 countries, Ecma agrees that the DIS should allow for dates before 1900 and have proposed supporting a full range as specified by the ISO 8601 standard for dates.
b) Leap year calculation
ECMA-376, the original Open XML standard adopted by Ecma, treats 1900 as a leap year in order to maintain compatibility with earlier spreadsheet applications that included this error. This is an important compatibility consideration, but based on the comments received by many National Bodies on this issue, Ecma acknowledges that the date system should be correct. The newly defined date system described in the previous item treats 1900 correctly. The leap-year bug will be deprecated, as described in the next item.
Functionality extracted from the main specification
Many National Bodies identified specific functionality within the specification that reflected existing product defects or legacy application behaviors. These behaviors are important because they reflect the content in existing documents, but should not be perpetuated when creating new documents from scratch.
Following the precedent set by other ISO standards (such as SQL's ISO 9075:2003 Part 1 and C++'s ISO/IEC 14882:1998), Ecma is proposing changes to DIS 29500 that will more clearly distinguish defects and deprecated functionality from what will be best for new documents.
Issues related to the “leap year bug”, VML, compatibility settings such as “AutoSpaceLikeWord95” and others will be extracted from the main specification and relocated to an independent annex in DIS 29500 for deprecated functionality.
The intent of this Annex is to enable a transitional period during which existing binary documents being migrated to DIS 29500 can make use of those deprecated features, while noting that new documents should not use them. Accordingly, the conformance clause will also be changed to state that new documents created from scratch should not use functionality described in the new annex. This will ensure that existing content can still be successfully migrated, but will also ensure that bugs or legacy semantics will not be perpetuated by the Open XML standard.
Many National Bodies commented about the role of VML in the specification. Some have asked for it to be removed completely, whereas others have asked for VML to be treated in an annex only. Ecma agrees and will remove VML from the main specification. As suggested by many National Bodies, we will also make the necessary changes to enable the usage of DrawingML everywhere VML was previously used.
VML will be moved to the new annex for deprecated functionality. This will ensure that new documents will fully utilize DrawingML, as provided for by the new conformance clause. This will also enable a transitional period during which existing binary documents being migrated to DIS 29500 can make use of VML. This is a significant change for
b) Compatibility settings
Many National Bodies requested more complete documentation for some legacy application compatibility settings in DIS 29500, such as “AutoSpaceLikeWord95”, “truncateFontHeightsLikeWP6 “and others. Ecma agrees with this comment, and will provide the full information necessary to implement all compatibility settings within
DIS 29500. This will enable implementers to achieve more full-fidelity compatibility with existing documents, and ensure DIS 29500 can be fully implemented without dependency on legacy products. In addition, we will remove all legacy application compatibility settings from their current locations in the specification, moving them into the new annex for deprecated functionality. The new conformance clause provides for new documents to be created without using the compatibility settings. This is a significant change for DIS 29500.
3 Conformance and Organization of the specification
National Bodies expressed a need to more clearly identify how developers can implement only the areas of the specification that are important to them; for example, many developers want to implement only word processing documents, but not spreadsheets or presentations. Two significant changes are proposed to help developers implement those areas they deem most appropriate:
Many National Bodies commented on the conformance clause for DIS 29500, saying that it was too broad to be reasonably implemented and asserting that it should address semantics as well as syntax. Ecma agrees with these comments, and will change
DIS 29500 to have more specific conformance clauses. WordProcessingML, SpreadsheetML, PresentationML, OPC and Extensibility will have separate conformance classes. Additional conformance classes for other parts of the standard may be added if needed for more granularity. The conformance clause has also been changed to include semantic conformance and to provide for new documents to be created without using the deprecated functionality described in the new Annex.
Many National Bodies commented that the modular nature of DIS 29500 should be treated as a multi-part standard, to isolate specific technologies into separate specifications. Ecma agrees with this comment and proposes the following dispositions for these comments. DIS 29500 will be reorganized into three distinct parts:
DIS 29500-1 will consist of the WordProcessingML, SpreadsheetML, PresentationML, and supporting SharedML specifications; DIS 29500-2 will consist of the OPC (packaging) specification; and DIS 29500-3 will contain the Extensibility specification. This reorganization will simplify DIS 29500 for implementers.
The items outlined above are just a subset of the 2298 proposed comment dispositions published to date. Ecma TC45, together with the Project Editor, will continue to review the remaining National Body comments in the weeks ahead, and publish additional proposed dispositions as quickly as possible leading up to the mid-January deadline.
We look forward to continued cooperation and collaboration with ISO, IEC, and ISO/IEC JTC 1.
Tom Ngo (NextPage)