Technical Change Report

This section describes the changes between Version 2.3 and Version 3.0 of the Archiving Tag Set and the Archiving and Interchange Tag Suite base modules. The changes are described in terms of the DTD modules, since the DTD is the primary modeling mechanism and the XSD and RELAX NG schemas are derived from these modules. First the base Suite changes are described, which are used by all Tag Sets unless explicitly overridden. An example of such a universal change is changing the name of a base module or the name of an element used in all the Tag Sets. Then the Archiving-specific changes are described.

Version 3.0 of these Tag Sets is a departure from all previous releases. All prior versions of the Tag Sets have been document-backward compatible, meaning that, although the Tag Sets have been modified several times, a document that was valid to one version of the tag sets was valid in all subsequent versions. All new elements and structures have, in previous versions, been made optional so there was never a need to modify the backfile to be conformant to the latest Tag Set. In Version 3.0 for the first time, changes have been made that render documents that were valid to a prior version invalid to 3.0. The idea was to make the Tag Sets as logical, internally consistent, and complete as possible going forward. Therefore, users of previous versions, if they choose to accept and integrate Version 3.0, will require changes to the backfile to make it compliant or a before-3.0-and-after-3-0 divergence in their repository. The decision to update to Version 3.0 is left up to each publisher and archive.

The type of changes that cause a document valid according to a previous version to be invalid in Version 3.0 include:

In current planning, the subsequent 3.x releases will be backward-compatilble with Version 3.0, so that the Tag Sets will be back to the pattern of incremental, backward-compatible growth.

Subsidiary sections:

General Changes

Archiving-specific Changes