This section describes the changes between Version 2.3 and Version 3.0 of the Publishing 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 Publishing-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:
- Element name changes — An element that has been in the Tag Sets from the beginning has had its name changed, for example chem-struct-wrapper has been renamed to be <chem-struct-wrap>.
- New container elements — Many elements that were direct children of their parents are now grouped together in new container elements. For example,
translated titles and subtitles are now grouped into a single, overarching container so that a title and its subtitle can
be distinguished form all other title/subtitle pairs.
- Children grouped — Many elements that used to be direct children of their parents are now grouped together in new container
elements. For example, all translated titles used to be followed by all translated subtitles. Now, a translated title and
its subtitle are grouped into a single, overarching container so that a title and its subtitle can be distinguished from all
other title/subtitle pairs.
- Model tightening — When new features were added to previous versions of these Tag Sets, for example, when a new container
element was added to contain elements that had previously been direct children, then both the container and the direct children
were allowed in the model, for reasons of backward compatibility. This version removed such duplication and allows only the
grouped version, for example, the <copyright-statement> inside <article-meta> is now allowed only inside <permissions> and not also as a direct child of <article-meta>.
- Replacement elements — Some elements have been replaced by more general or more functional alternatives, for example:
- The simple grant-num and grant-sponsor were deleted in favor of a more full-bodied funding model that includes, for example, sponsorship statements, principal investigator,
and access charge information.
- The very specific <time-stamp> and <access-date> elements within a citation were replaced with a more general <date-in-citation> that can be used to tag all dates except publication dates within a citation. The date type of this new date should be identified
with a type attribute.
- The elements identifying a citation within a reference list have been renamed and remodeled. The only holdover from previous
Tag Sets is the <nlm-citation>, which will now be deprecated in favor of the <element-citation> element.
- Module name changes — For the first time, the DTD and schema module names include the version of the Tag Set being defined, for example “list3.ent” where the old name was “%list.ent;”.
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.