6 January 1997 Backwards-incompatible changes to DocBook that are planned for V4.0: - The DocInfo element will be split out into ChapterInfo, AppendixInfo, etc. ArtHeader will be renamed to ArticleInfo. SeriesInfo may be discarded because it has become a special case of BiblioSet. BookBiblio will be discarded in favor of a new, more inclusive, structure for BookInfo (and for ArticleInfo, whose earlier ArtHeader form contained BookBiblio). - The %article.class; entity may be removed from the Book content model, and made part of a new top-level document hierarchy. - The %nav.class; entity, which appears in several divisions, will allow ToCchap instead of ToC. - MsgText will be moved from tech.char.class to a more appropriate parameter entity. - The following elements will have their content constrained to the %smallcptr.char.mix; mixture: Action, Command, Database, Filename, Hardware, Interface, KeyCap, Literal, Option, Parameter, Property, and SystemItem. - AuthorBlurb and Affiliation will be removed from %person.ident.mix; and a new wrapper element created to allow association of those two elements with Author name information. - Epigraph will be disallowed from appearing in BlockQuote. - Comment will be renamed to Remark and will be excluded from itself. - GlossTerm will be excluded from itself, and may be split into an element that appears in a Glossary and an element that can appear in the main text. - The Subject attribute on GlossDef will be renamed Keyword. - Two SegTitle elements will be required in SegmentedList. - Graphic and InlineGraphic will be declared EMPTY. This change will require that end-tags be removed and that any embedded graphic content be stored outside the SGML source and pointed to from an Entityref or Fileref attribute. - The OptMult and ReqMult values for the Choice attribute on Group will be removed. Use the Rep attribute instead to indicate that the choice is repeatable. - The content model group inside FuncSynopsis starting with FuncDef will not be available; you will have to use FuncPrototype. Also, you will be able to have a mixture of FuncPrototypes and FuncSynopsisInfos (this is not backwards-incompatible all by itself). - The EnvironVar and Prompt values for the Class attribute on SystemItem will be eliminated; use the EnVar and Prompt elements instead. - All link elements will be excluded from themselves and each other.
