Open Packaging Conventions & Open XML Markup Compatibility

As you may already know, the Open Packaging Conventions and Open XML Markup Compatibility specifications are an important foundation to both the XML Paper Specification and the Office Open XML document formats. The Office Open XML document formats have been going through a standardization effort with Ecma International. To complete that effort, we have included both the Open Packaging Conventions and the Open XML Markup Compatibility specificatons as part of that standard.

What this practically means to developers of software based these two specifications (and the XPS specification since it relies on them) is that you should follow the most recent draft of the technical committee in your implementations. All new updates to these documents following v0.85 will happen only in that draft. The most recent working draft of these documents, currently named TC-45/2 and TC-45/5, is version 1.4 and includes all the latest revisions since v0.85. We do not plan to maintain a parallel copy of this documentation going forward.

Readers of these documents will note that they've undergone an extensive effort to be much more precise in the use of normative and informative language. This mostly has resulted in a fairly broad number of changes in the language used; however, the meaning should be preserved except where intentional, yet relatively minor, changes were made. We will assemble and post a summary of the meaningful changes here on this blog after the Labor Day holiday.

The use of the conformance language in both specs has changed to follow the Ecma conformance language style. The term MUST has been replaced by "shall," the term "MAY" has been replaced by the terms "can" or "might," and the term "SHOULD" is now simply "should". In the Open Packaging Conventions, it became obvious that the conformance rule number scheme utilizing chapter numbers no longer made sense given the addition of several new clauses introducing the spec, so we have made a one-time change in the numbering scheme, as described in the standard. We will shortly post a mapping of old conformance rule numbers to new conformance rule numbers to this blog for your convenience. Be aware that the conformance "violate one rule" documents included in the just-released WDK Release Candidate are based on the new rule numbers.

In addition to the stylistic changes to the Open XML Markup Compatibility specification, we invested a lot of effort to be much more strict in our usage of terminology, which we hope has resulted in a much clearer and more technically precise document. In particular, we took advantage of the release of the clarifications and terms in the new XML 1.0 Specification (Fourth Edition) and the Namespaces in XML 1.0 Specification (Second Edition), released on August 16th, to clarify our terminology usage.

Questions are welcome at