Changes Made from V2.1 to V2.2.1

From V2.1 to V2.2.1 most changes were minor, although a few were backwards incompatible. (As noted in the Section called Revision and Maintenance Policy in Chapter 1, future backward incompatible changes are now made only in major DTD revisions.) The following changes in that release were backwards incompatible:

• The elements Character, Charset, Font, and Glyph were removed, as were EventStructure, EventType, Mask, and ProtocolRequest.

• The FAXTILE notation was removed.

• IndexTerms were disallowed from appearing in Highlights.

• Footnote was excluded from itself (beware, all you folks who were footnoting your footnotes!).

• The Mark attribute on FootnoteRef (which is to be renamed Label in V3.0) was changed to #IMPLIED from #CONREF.

• The Width attribute was removed from ScreenShot.

• Logo was removed from the Class attribute on ProductName and Trademark.

• The Linkend attribute was removed from ToCFront.

• The Linkend and PageNum attributes formerly found on the components of ToC were moved to the new ToCEntry element.

The following were the significant backwards-compatible changes in V2.2.1:

• A notation declaration was added for CGM-BINARY.

• ProductName and ProductNumber were made available within %docinfo.content.gp;, and thus as inline markup in most places.

• Optional was made available as inline markup.

• Subtitle was expanded to be able to contain inline markup.

• All the link elements were expanded to be able to contain inline objects, and were given common attributes. XRef was given common attributes in addition to Linkend and Endterm.

• LegalNotice was expanded to be able to contain many additional block-oriented elements.

• In Revision, AuthorInitials and RevRemark were made optional.

• Application, CiteTitle, and Quote were expanded to be able to contain a wider range of inline elements.

• Subscript and Superscript were expanded to be able to contain Emphasis.

• GlossSee and GlossSeeAlso were expanded to be able to contain inline elements.

• PrimaryIE, SecondaryIE, TertiaryIE, SeeIE, and SeeAlsoIE were expanded to be able to contain inline elements, and their Linkends attributes were changed to #IMPLIED from #REQUIRED.

• Contrib was created and included in the content models of Author, Editor, and OtherCredit, as a place to store information about the contributions of these parties to the document in question. It contains plain text.

• GlossList was created: it's a set of GlossEntries and may be used anywhere lists are allowed.

• InformalExample was created, as a parallel to other informal block-oriented elements. It's just like Example, but without a title.

• ToCentry was created and added to all the components of ToC, to hold the actual entries in a Table of Contents. It may contain plain text and in-line elements.

• Address was expanded to be able to contain the new OtherAddr for modes of addressing not now covered by other elements.

• Block-oriented elements were allowed to occur between SubSteps.

• Para was expanded to be able to contain InlineGraphic and InlineEquation.

• Entry (a table cell) was expanded to be able to contain elements from %code.example.gp; (LiteralLayout, ProgramListing, Screen, and ScreenShot).

• Glossary was changed to be able to close with an optional Bibliography.

• A RefNameDiv was allowed to contain more than one RefClass.

• Editor and OtherCredit were added as allowable contents in AuthorGroup.

• A new Scope attribute was added to IndexTerm with the allowed values All, Global, and Local (the default is #IMPLIED), to meet the case of IndexTerms that should be used to generate, e.g., an index for a Book (Local) but not an index for a Set (Global) or vice versa; the value All should be used when the IndexTerm should appear in all generated indices. You should define your implementation's default accordingly.

• Also, a new Zone attribute, with #IMPLIED IDREFS values, was added to IndexTerm. This attribute is to be used when it is desired to attach indexing information to SGML elements rather than, or in addition to, placing IndexTerms in the flow of the text so as to be sure page references are generated correctly. Zone could be used to attach keywords to sections and paragraphs, for example, facilitating the assembly of nonstructural views of the indexed text.

• The RenderAs attribute default for Sect1–5 and Bridgehead was changed to #IMPLIED (from the same value as the element's generic identifier, or Other, in the case of Bridgehead—there might be some backward incompatibility for BridgeHead).

• A SrcCredit attribute was added to Graphic, InlineGraphic, and LoTEntry for storage of information crediting the source of an image.

• Many more inline elements were given common attributes.

• The ID attributes on Footnote and BeginPage were changed to #IMPLIED from #REQUIRED.

• The PageNum attribute on Anchor was changed to #IMPLIED from #REQUIRED.

• Part was added as a defined value for the Pubwork attribute on CiteTitle.

• GlossEntry was given a SortAs attribute, like IndexEntry.

• The Subject attribute on GlossDef was changed from NMTOKENS to CDATA.