Abstract is a summary of a document's content. It contains Paras and may bear a Title. Abstract has common attributes. Acronym is a pseudoword made up of the initials or initial parts of a conventional series of words. For purposes of the DocBook DTD Acronym may also be a string of initials. Acronym contains plain text and has common attributes. Action is a function to be invoked in response to a user event. It contains plain text and has common and HasRefEntry attributes. Anchor marks a target for a Link, and may appear almost anywhere. Anchor has no content, and no end tag. Anchor has common and Pagenum attributes. Appendix may contain anything found in a Chapter. It may have a DocInfo and must have a Title and may have a TitleAbbrev. Appendix has common and Number attributes. Application is the name of a software program that does something useful. Application may contain plain text and has common attributes. Author is part of DocInfo and consists of one or more optional Firstnames and an optional Surname element. Author also occurs in BiblioEntry. It has common attributes. <AUTHOR><FIRSTNAME>Marmaduke Anthony</FIRSTNAME> <SURNAME>Pickthall</SURNAME></AUTHOR> AuthorBlurb is a short description of a document's author. It contains Paras and may bear a Title. AuthorBlurb has common attributes. AuthorInitials indicate the author of a Revision or Comment. AuthorInitials contains plain text and has common attributes. BiblioEntry is an entry in a Bibliography. For flexibility, it may contain a TitleAbbrev, must contain at least one of Author, CorpAuthor, Editor, or Title, may have any or all of Subtitle, Date, and Publisher, and following all of that, plain text. BiblioEntry has common attributes. Bibliography may be a book component on its own, or it may appear within a Preface, Chapter, or Appendix. It may have a DocInfo, a Title and a TitleAbbrev, may have one or more introductory Paras, and contains BiblioEntries. No provision has been made for bibliographies that are divided into sections. Bibliography has common attributes. BlockQuote is a quotation set off from the main text, rather than occurring in-line. It may be titled, and may contain anything found in a Sect except another Sect---that is, it may contain Paras, lists, and so forth. BlockQuote has common attributes. Book is NOT THE SAME AS DOCBOOK. A Book is loosely defined as having a required DocInfo, then an optional ToC, any number of LoTs, any number of Prefaces, one or more Chapters, the following: Appnedix, Bibliography, and then, in order, any number of References, Appendixes, Glossaries, Bibliographies, and Indexes. Book has common and Number attributes (you can supply the number of a Book through this attribute or as the content of the VolumeNumber element in DocInfo). BookAcronym is an optional part of BookTitle, part of DocInfo, and may be used alongside or in preference to TitleAbbrev. BookAcronym contains plain text and has common attributes. BookTitle is part of DocInfo, and contains, in order, a mandatory Title and optional Subtitle, TitleAbbrev, ReleaseInfo, and Book Acronym. BookTitle may also appear as the first element of DocBook. BookTitle has common attributes. Button is a button in a graphical user interface. It contains plain text and has common attributes. Caution is an admonition set off from the text and supplied with a title, which is ``Caution'' unless another Title is supplied explicitly. The contents of a Caution may include Paras, lists, and so forth. Caution has common attributes. Chapter may contain anything except higher-level elements such as Part, Book, and Set. It may have a DocInfo, must have a Title, and may have a TitleAbbrev. Chapter has common and Number attributes. Character is a character, that is, an element of a writing system. Characters may belong to Charsets, and in some contexts one may speak of fonts as representing characters. But cf. Glyph, Font. Charset is a conventionally defined set of characters, (not a font). Charset contains plain text and has common attributes. Citation is any in-line bibliographic reference to another published work that uses a reference string, such as an abbreviation in a Bibliography. Citation may contain plain text only, and has common attributes. CiteBook is the name of another book (or journal) cited in the text. CiteBook may contain in-line elements, and has common attributes. CiteChap is a reference to a specific chapter (or other component) of any book cited in the text, including the book in which the CiteChap appears. CiteChap may contain in-line elements, and has common attributes. CiteRefEntry is a reference to a RefEntry in any book cited in the text, including the book in which the CiteRefEntry appears. CiteRefEntry may contain in-line elements, and has common attributes. CiteSect is a reference to a specific section of another document cited in the text, including the document in which the CiteSect appears. CiteSect may contain in-line elements, and has common attributes. Classname is the name of the class to which a program component belongs. Classname contains plain text and has common and HasRefEntry attributes. Command is the name of an executable program, or the entry a user makes to execute a command. Command may contain plain text, FunctionParam, VarParam, Anchor, Optional, and Option, and has common and HasRefEntry attributes. Comment is a remark made within the document file that is intended for use during interim stages of production. A finished piece of computer documentation intended for an end user would have no visible Comments. Comment may appear almost anywhere, and may contain almost anything below the Section level; it has common attributes. ComputerOutput is data presented to the user by a computer. It may contain plain text and Anchors, and has common and HasRefEntry attributes. Constant is a fixed value. Constant contains plain text and has common and HasRefEntry attributes. Copyright is part of DocInfo and consists of one or more Years and any number of Holders. Copyright has common attributes. CorpAuthor is the corporate author of a book, for use in DocInfo or BiblioEntry. It has common attributes. CorpName is the name of a corporation. It contains plain text and has common attributes. Date appears in DocInfo, BiblioEntry, and Revision, and contains plain text. It has common attributes. No provision has been made for representing eras; you could include this information along with the date data. DbField is the name of a field in a database. DBField contains plain text and has common and HasRefEntry attributes. DbName is the name of a database or database file. DbName contains plain text and has common and HasRefEntry attributes. DbRecord is the name of a record in a database. DbRecord contains plain text and has common and HasRefEntry attributes. DbTable is the name of a database table. DbTable contains plain text and has common and HasRefEntry attributes. DocBook is the base document element for this DTD. It is only a wrapper and has no semantic value. DocInfo is a book component, containing one or more of the following: Author, AuthorInitials, BookAcronym, BookTitle, Copyright, CorpAuthor, CorpName, Date, Editor, Edition, InvPartNumber, ISBN, LegalNotice, OrgName, PrintHistory, ProductName, ProductNumber, Publisher, PubsNumber, RevHistory, Series, and VolumeNumber. No order is enforced among these elements, but you are urged to begin with BookTitle and Author(s). DocInfo has common attributes. Edition is the edition of a document. It contains plain text and has common attributes. Editor is like Author, an element of DocInfo and BiblioEntry. It consists of one or more optional Firstnames and an optional Surname element. It has common attributes. Emphasis is provided for use where one would traditionally employ italics (more rarely, bold) to emphasize a word or phrase. Emphasis may contain only plain text; it has common attributes. Epigraph is to be used for a brief section of poetry or prose at the start of a chapter. It contains Paras, and has and common attributes. Equation is a mathematical equation set off on a line by itself, or occurring in-line. An Equation has an optional Title and TitleAbbrev, and contains a Graphic, q.v. Equation has common attributes. Error is an error reported by a computer. Error contains plain text and has common attributes. EventStructure is the code that defines an Event. EventStructure contains plain text and has common and HasRefEntry attributes. EventType is a classification of an event. EventType contains plain text and has common and HasRefEntry attributes. Example is intended for sections of program source code that are provided as examples in the text. A Example has an optional Title, optional TitleAbbrev, and one or more Screens, LiteralLayouts, or ProgramListings, in any combination. Example has common attributes and bears the ``linespecific'' Notation attribute. ExternalLink is like Link, q.v., except that its Linkend and Endlink attributes are not defined as SGML IDREFs; this is so you can make reference to external documents without incurring parsing errors. Figure is an illustration. A Figure must have a Title, and may have a TitleAbbrev; it may then contain one or more of the following: BlockQuote, Comment, Equation, Example, FigureFileRef, Graphic, IndexTerm, LiteralLayout, ProgramListing, Screen, Synopsis, and Table. It has an ID attribute, and also Height, Width, Align, and Float attributes. To reference an external file containing graphical content use the Graphic element. Filename is the name of a file, including pathname if this information is present. Filename may contain plain text, FunctionParam, VarParam, and Anchor, and has common and HasRefEntry attributes. Firstname is part of Author and Editor, q.q.v. It contains plain text and has common attributes. FirstTerm is to be used for the first occurrence of a word in a given context, when the style of the document is such that these first occurrences are differentiated in some manner. A FirstTerm may contain plain text only, and has common attributes. Footnote is the text of a footnote. The point in the text where the mark for a specific footnote goes is indicated by FootnoteRef; the text of the Footnote may appear somewhere else in the file. A Footnote may contain all of the permissible contents of Paras. Footnote has common and Number attributes. Font is a collection of Glyphs, q.v. Font contains plain text and has common attributes. FootnoteRef indentifies the location for a footnote mark. It may contain plain text, which is the mark to be displayed, or it may be empty. It has ID, Linkend, and Mark attributes: the Linkend attribute has as its value the ID of the associated Footnote, and the Mark attribute provides another way of indicating the contents of the mark (such as an asterisk, *). ForeignPhrase is any word or words from a language other than that of the document which it is desired to mark off in some way. In English, inter alia and c'est la vie are ForeignPhrases. ForeignPhrase contains plain text and has common attributes. Function is a subroutine in a program or external library. Function may contain plain text, FunctionParam, VarParam, and Anchor, and has common and HasRefEntry attributes. FunctionParam identifies an argument for a Function. It may contain plain text, Subscript, and Superscript, and has common attributes. Glossary may occur within a Chapter, Appendix, or Preface, or may be a book component in its own right. It contains an optional DocInfo, optional Title and TitleAbbrev, may contain any number of Paras, and then consists of GlossaryEntries. No provision has been made for Glossaries divided into sections. Glossary has common attributes. GlossaryDef is the definition attached to a GlossaryTerm in a GlossaryEntry, which occurs in a Glossary. It may contain in-line elements, and has common attributes. GlossaryEntry is an entry in a Glossary, containing a GlossaryTerm and GlossaryDef. Please note that GlossaryEntry occurs in a Glossary, not in the text of (e.g.) a Chapter (although a Glossary may be included within a Chapter). GlossaryEntry has common attributes. GlossaryTerm is an in-line element for tagging terms in the text of a Chapter (for example) that are glossed in a Glossary, and also for tagging those terms in GlossaryEntries, in the Glossary itself. As you may not want to tag all occurrences of these words outside of Glossaries, you might consider GlossaryTerm, when used outside of Glossaries, to be similar to FirstTerm, except that GlossaryTerm may contain other in-line elements. GlossaryTerm has common attributes. Glyph is a mark, a component of a font. A character or ligature might be made up of one, two, or more Glyphs. Glyph contains plain text and has common attributes. Cf. Character. Graphic may occur within a Figure, Table, Screen, Paragraph, or Equation, to enclose graphical data or to point to an external file containing the contents of one of these elements. Graphic contains CDATA (data in which SGML entities and tags, other than the Graphic end tag, are not recognized by the SGML parser) and has format, Fileref, Entityref, and ID attributes. The format attribute may have the value of GIF, TIFF, CGM, DVI, EPS, TEX, TBL, EQN, DITROFF, or PS. If it is desired to point to an external file, a filename may be supplied as the value of the Fileref attribute, or an external entity may be supplied as the value of the Entityref attribute. Hardware is any name for a physical part of a computer system. It may contain plain text, FunctionParam, VarParam, and Anchor, and has common attributes. Highlights is a list of main points that are discussed a book component such as a Chapter. It may contain Paras and lists, and has common attributes. Holder is part of Copyright and is the name of the holder of the copyright of the document. It may contain plain text only, and has common attributes. Honorific is a person's title, to be used as part of Author or Editor. It has common attributes. HWapplic describes the hardware to which given context (such as a RefEntry) is relevant. RefClass is a good place to put HWapplic information. HWapplic contains plain text and has common attributes. Icon is the name of an icon or image presented on a computer screen. Icon contains plaint text and has common attributes. Important is an admonition set off from the text and supplied with a title, which is ``Important'' unless another Title is supplied explicitly. The contents of an Important may include Paras, lists, and so forth. Important has common attributes. Index may occur within a Chapter, Appendix, or Preface, or may be a book component on its own. It contains an optional DocInfo, Title, and TitleAbbrev, may contain any number of Paras, and then consists of IndexEntries. No provision has been made for Indices divided into sections. Index has common attributes. IndexAs may be nested within the IndexTerm components Primary, Secondary, and Tertiary to indicate an alternate string by which the indexed term (the other content of Primary, Secondary, or Tertiary) should be indexed in the Index. You might want to use this element if you tag IndexTerms in the body of the text, rather than as separate elements. IndexAs contains in-line elements, and has common attributes. IndexEntry is a part of Index, and contains a PrimaryIE, which may be accompanied by SecondaryIE, TertiaryIE, SeeIE, and SeeAlsoIE. It has common attributes. IndexTerm is a word or phrase to be indexed. IndexTerm appears in the text, not in the Index; you can apply IndexTerm to words in the flow of text or include IndexTerms as separate elements. Primary, Secondary, and Tertiary index items are nested within this tag, as are See and SeeAlso items. IndexTerm has common, Span, and PageNum attributes. The Span attribute, which may have the value Start or End, may be used for showing a span of text to be indexed. The PageNum attribute may be used to indicate the page on which the indexed term is found in print. Interface is the name of any part of a graphical user interface, such as a button, icon, menu, menu selection, or window; a more specific element may be used instead. Interface plain text, FunctionParam, VarParam, and Anchor, and has common and HasRefEntry attributes. InterfaceDefinition is a specification for a graphical user interface. It contains plain text and has common and HasRefEntry attributes. InvPartNumber is an inventory part number, which may occur in DocInfo. It contains plain text and has common attributes. ISBN is part of DocInfo, and should be used for the International Standard Book Number of the document if it has one. (You could use it for an ISSN, also.) ISBN contains plain text only, and has common attributes. ItemizedList is a list in which each item is marked with a bullet, dash, or other dingbat (or no mark at all). It consists of one or more ListItems. A ListItem in an ItemizedList contains Paras and other objects, which may in turn contain other lists; an ItemizedList may be nested within other lists, too. ItemizedList has common attributes and a Mark attribute. Your application might supply the mark to be used for an ItemizedList, but you can use this attribute to indicate the mark you desire to be used (such as •); for no mark at all, use the attribute but give it no value. ItemizedList may be nested within Task, so as to provide a Title and introductory matter. Keycap is the text printed on a physical key on a computer keyboard, not necessarily the same thing as a Keycode. Keycap contains plain text and has common and HasRefEntry attributes. Keycode is the computer's numeric designation of a key on a computer keyboard. Keycode contains plain text and has common and HasRefEntry attributes. Keysym is a key symbol name, which is not necessarily the same thing as a Keycap. The Keysym for the H key (Keycap H) is h, for example. Keysym contains plain text and has common and HasRefEntry attributes. LegalNotice is part of DocInfo, for acknowledgement of trademarks and so forth. It consists of Paras and has common attributes. LineAnnotation is a writer's or editor's comment on a line of program code within an Example, ProgramListing, or Screen. The code's own comments are not LineAnnotations. LineAnnotation contains plain text and has common attributes. Link is a hypertext link. It may contain in-line elements and has Endterm, Linkend, and Type attributes. The required Linkend attribute specifies the target of the link, and the optional Endterm attribute specifies text that is to be fetched from elsewhere in the document to appear in the Link. You can also supply this text directly as the content of the Link. The use of the optional Type attribute is undefined, allowing you to create local link types. ListItem is a wrapper for the elements of item in an ItemizedList or OrderedList; it also occurs within VarListEntry in VariableList. It may contain just about anything except Sects and book components. ListItem has common attributes. Literal is any literal string, used in-line, that is part of data in a computer. This may be as precise as the value of an argument, but Literal may also be used as a catch-all element. Literal may contain plain text and Anchor; it is not meant as a wrapper for in-line elements. Literal has common and HasRefEntry attributes. LiteralLayout is the wrapper for lines set off from the main text that are not tagged as Screens, Examples, or ProgramListing, in which line breaks and leading white space are to be regarded as significant. LiteralLayout contains in-line elements; it has common attributes and the ``linespecific'' Notation attribute. LoT is the generic tag for such things as a List of Figures or List of Tables. An LoT may occur within a Chapter, or Appendix, or may be a book component on its own. It contains an optional DocInfo, Title, and TitleAbbrev, followed by multiple LoTentries. LoT has common attributes. LoTentry is an element of LoT, and contains the text of the thing to be listed, including, if desired, in-line elements. LoTentry has common and PageNum attributes. Macro is the name of a computer macro. It contains plain text and has common attributes. ManVolNum, which is specific to UNIX man pages, designates the section of a complete set of reference pages that a reference page belongs to. It appears within RefMeta, contains plain text, and has common attributes. Mask specifies which values in a specified structure should be read when updating resource values. Mask contains plain text and has common and HasRefEntry attributes. Menu is part of a graphical user interface, containing choices of actions for the user. Menu contains plain text and has common and HasRefEntry attributes. MenuItem is a choice in a menu. MenuItem contains plain text and has common and HasRefEntry attributes. Note is a message to the user, set off from the text and supplied with a title, which is ``Note'' unless another Title is supplied explicitly. The contents of a Note may include Paras, lists, and so forth. Note has common attributes. Option is a option to a Command (in the Command ``ls -l'' ``-l'' is an Option), but is not nested within Command. It may contain plain text, FunctionParam, VarParam, and Anchor, and has common and HasRefEntry attributes. Optional is for use in Synopsis, as in a RefEntry, where optional parameters conventionally are shown in square brackets. Optional should replace those brackets; it may contain any element listed in the parameter entity computerterms.gp, and has common attributes. OrderedList is a numbered or lettered list, consisting of ListItems. A ListItem in an OrderedList contains Paras and other objects, which may in turn contain other lists; an OrderedList may be nested within other lists, too. OrderedList has common attributes, along with a Numeration attribute, which may have the value Arabic, Upperalpha, Loweralpha, Upperroman, or Lowerroman. The default is Arabic. OrderedList also has an InheritNum attribute, specifying that for a nested list the numbering of ListItems should include the number of the item within which they are nested (2a, 2b, etc., rather than a, b, etc.). Orderedlist also has a Continuation attribute, with values Yes or No, which may be used to indicate whether the numbering of a list begins afresh (No) or continues that of the immediately preceding list (Yes). The default is No, so you need supply the Continuation attribute only if your list continues the numbering of the preceding list. OrgName is the name of an organization that is not a corporation (cf. CorpName), for use in DocInfo. It contains plain text and has common attributes. OSname is the name of an operating system. It contains plain text and has common attributes. OtherName is provided as an alternative to Firstname and Surname in Author and Editor. It has common attributes. Para is a paragraph. It may have a Title, by means of which authors may evade the Sect hierarchy, as with a ``bridgehead.'' Para may contain any in-line element, any list, Graphic, Equation, Synopsis, Table, BlockQuote, ProgramListing, LiteralLayout, Screen, and Figure. Abstract, AuthorBlurb, Caution, Important, Note, and Warning are excluded, as are Sects and higher-level elements. Para has common attributes. Part may be used to compose a Book. It contains a Title, an optional TitleAbbrev, an optional PartIntro, followed by two or more Chapters or Appendices. Part has common and Number attributes. PartIntro is a part of Part, and may also appear in Reference. In Part, it should introduce the contents of the Part. It may contain just about anything except Sects. PartIntro has common attributes. Preface is a book component, just like a Chapter, q.v. Use the Title element to provide the word ``Preface'' or other string as desired. Preface has common attributes. Primary is a word or phrase occurring in the text that is to appear in the index under as a primary entry. It must be nested within IndexTerm tags. Primary may contain in-line elements and IndexAs, q.v. Primary. Primary has common and HasRefEntry attributes. PrimaryIE is a primary entry in an Index, not in the text. It may contain only plain text, and has common attributes and a Linkends attribute, which has the value of some list of element IDs. PrintHistory is part of DocInfo, q.v. It contains Paras and has common attributes. ProductName is a formal name for any product, part of DocInfo. It contains plain text and has common attributes. ProductNumber is a number assigned to a product, part of DocInfo. It contains plain text and has common attributes. ProgramListing contains a listing of a program, including LineAnnotations. Line breaks and leading white space are significant in a ProgramListing. Programlisting may contain in-line elements, and has common attributes. Prompt is a prompt appearing on a computer screen, such as the percent sign (%), including any other text appearing there (marmaduke%). Prompt may contain only plain text and has common attributes. Property is the name of a defined set of data associated with a window. Property may contain in-line elements, and has common attributes. ProtocolRequest is a message sent from a program to the server. ProtocolRequest contains plain text and has common attributes. PubsNumber is a number assigned to a publication other than ISBN, for use in DocInfo. Cf. also InvPartNumber. PubsNumber contains plain text and has common attributes. Publisher is an element of DocInfo and BiblioEntry. It may contain plain text only, and has common attributes. Quote is supplied for in-line quotations. For block quotes use BlockQuote. Quote may contain in-line elements and has common attributes. RefClass is an element of RefNameDiv, in which the applicability or scope of the topic of a RefEntry may be indicated (such as the element SWapplic or a string such as ``LocalBlocking''). It may contain in-line elements and has common attributes. RefDescriptor is a substitute for RefName to be used when a RefEntry covers more than one topic and none of the topic name is to be used as the sort name. RefDescriptor contains plain text and has common attributes. RefEntry is a reference page. RefEntry has common attributes. For more on RefEntries see version 1.0 of the Guide to the DocBook DTD. Reference is a collection of RefEntries. It may be a book component on its own, or it may appear within a Preface, Chapter, or Appendix. Reference has an optional DocInfo, a required Title, an optional TitleAbbrev, an optional PartIntro, and one or more RefEntries. Reference has common attributes. RefFileName is the primary name given to the reference page for sorting and indexing. It may be the same as the first of the RefNames, or it may be the same as the RefDescriptor. RefFileName may contain only plain text, and has common attributes. RefMeta is the first major division of a reference page, in which metainformation about the reference page is supplied. RefMeta is optional, and has common attributes. RefMiscInfo marks information in RefMeta that may be supplied by vendors, such as copyright, release date, revision date, print status, operating system, hardware architecture, or a descriptive phrase for use in a print header. It may contain only plain text, and has common attributes. RefName is the name of the subject or subjects of a reference page, and appears within RefNameDiv. It may contain plain text and in-line elements, and has common attributes. RefNameDiv is the second major division of a reference page, in which the name (RefName) or names of the subject or subjects of the reference page are given, along with a RefPurpose. RefNameDiv has common attributes. RefPurpose is a short phrase describing the subject of the reference page. It follows the RefNames in the RefNameDiv division. It may contain in-line elements, and has common attributes. RefSect1 is equivalent to a Sect1 in the DocBook DTD. It contains a Title, followed by any of the allowable contents of a Sect, except that only one level of subsection is allowed, called RefSect2. RefSect1 has common attributes. RefSect2 is equivalent to a Sect2 in the DocBook DTD, and may occur within RefSect1 or RefSynopsisDiv. It may contain any of the allowable contents of a Sect, except that no further subsections are allowed. RefSect2 has common attributes. RefSynopsisDiv is the third major division of a reference page, in which the syntax of the subject of the reference page is indicated. It contains a Synopsis, and may have subdivisions, which must be RefSect2s, not RefSect1s (that is, RefSynopsisDiv counts as a RefSect1). RefSynopsisDiv has common attributes and a Name attribute, which may be either Synopsis or Syntax; the default is Synopsis. ReleaseInfo is an element of DocInfo, in which information about a particular version of a document may occur. It may contain only plain text, and has common attributes. Resource is a configurable setting available to a program that controls its behavior or appearance. Resource may contain plain text only, and has common attributes. ReturnValue is a value returned by a function. ReturnValue may contain plain text only, and has common attributes. RevHistory is a section of DocInfo consisting of Revisions. It has common attributes. Revision is an entry in RevHistory, describing some revision made to the text. A Revision has a mandatory Revisionnumber and Date, one or more sets of AuthorInitials, and a Revisionremark. It has common attributes. RevNumber is an element of Revision, q.v. It may contain only plain text, and has common attributes. RevRemark is an element of Revision, describing the Revision. It may contain only plain text, and has common attributes. Screen is intended to represent what the user sees or might see on a computer screen. A Screen may consist of in-line elements (in which line breaks and leading white space are considered significant) or a ScreenInfo and a Graphic. Screen has common attributes and the Notation attribute ``linespecific.'' ScreenInfo is a part of Screen, q.v. A ScreenInfo indicates how the Graphic with which it is paired was created as a guide for future revisions. It may contain only plain text, and has common attributes. Secondary is a word or phrase in the text that is to appear in the index beneath a Primary entry. It must be nested within IndexTerm tags and must follow a Primary element. Secondary may contain in-line elements and IndexAs, and has common and HasRefEntry attributes. SecondaryIE is part of IndexEntry, like PrimaryIE, q.v. Sect1 marks a section of a document that begins with a first-level heading. Anything may occur within a Sect1 except a DocInfo, Preface, Chapter, Appendix, or another Sect1, including a Glossary, Bibliography, RefEntry, Reference, Toc, Index, or LoT. Sect1 must have a Title, which is the text of the heading itself, it may have a TitleAbbrev, and must include some content other than in-line elements and plain text; these must occur in Paras or other objects. Sect1--5 have common and Number attributes. Sect2 is a section beginning with a second-level heading, and must be nested within a Sect1. Allowable and required content for Sect2s are like those for Sect1s. Sect3. Cf. Sect2. Sect4. Cf. Sect2. Sect5. Cf. Sect2. No further subdivisions are supplied in the DocBook DTD. See is part of IndexTerm, indicating, for a word or phrase in the text, the index entry to which the reader is to be directed when he consults the stub index entry for another element within the IndexTerm. See must be nested within IndexTerm tags and must follow a Primary or Secondary element. See may contain in-line elements and has common and HasRefEntry attributes.. SeeAlso is like See, but indicates the index entries to which the reader is also to be directed when he consults a full index entry. SeeAlso must be nested within IndexTerm tags and must follow a Primary or Secondary element. SeeAlso may contain in-line elements and has common and HasRefEntry attributes. SeeAlsoIE is a ``see also'' entry in an Index, not in the text, occurring unnested within IndexEntry at the PrimaryIE or SecondaryIE level. It may contain plain text only, and has common attributes and a Linkends attribute, which has the value of some list of IndexEntry IDs. SeeIE is a ``see'' entry in an Index, not in the text, occurring unnested within IndexEntry at the PrimaryIE or SecondaryIE level. It may contain plain text only, and has common attributes and a Linkend attribute, which has the value of some IndexEntry ID. Seg is a component of a SegmentedList. Segs are the only content of a SegmentedList's SegListItems. They may contain in-line elements. Seg has common and HasRefEntry attributes. SegListItem is a list item in a SegmentedList. It consists of two or more Segs, and has common attributes. SegmentedList is a list of sets of units without additional text (and is thus different from the VarListItem, composed of Terms and ListItem, in a VariableList). A SegmentedList may be used to represent sets of information often presented as simple tables. A SegmentedList may have a Title and TitleAbbrev, followed by any number of SegTitles, and two or more SegListItems. SegmentedList has common attributes. SegTitle is a title that pertains to one Seg in each SegListItem: the first SegTitle to the first Seg, the second SegTitle to the second Seg, and so on. SegTitles may contain in-line elements, and are grouped at the beginning of a SegmentedList, before the SegListItems. SegTitle has common and HasRefEntry attributes. Series is part of DocInfo and names the publication series of which the book is a part. Series may contain only plain text and has common attributes. Set is a set of Books. It has an optional DocInfo and must contain two or more Books. Set has common attributes. Sidebar is a segment of text isolated from the narrative flow of the main text, typically boxed. A Sidebar may have a Title and a TitleAbbrev, and must have text formatted in some fashion: allowable contents include Paras, lists, Figures, and Tables. No Sects allowed. Sidebar has common attributes. StructField is a field in a Structure. It may contain plain text only, and has common and HasRefEntry attributes. StructName is the name of a Structure. It may contain plain text only, and has common and HasRefEntry attributes. Subscript tags subscripts. It may contain plain text and another Subscript, and has common attributes. Subtitle is for use in BookTitle. It contains plain text and has common attributes. Superscript tags superscripts. It may contain plain text and another Superscript, and has common attributes. Surname is an element of Author in DocInfo, supplied so that a group of documents may be indexed by their authors's surnames. It may contain plain text only, and has common attributes. SWapplic specifies the applicability of information given a software context. RefClass is a good place to put SWapplic information. SWapplic contains plain text only and has common attributes. Symbol is a name that is replaced by a value before processing. Symbol contains plain text and has common attributes. Synopsis marks the line or lines that provide the syntax of a command or function. It appears within RefSynopsisDiv, and may occur elsewhere in a document, too. Synopsis may contain in-line elements; within it, line breaks and white space are significant. It has common attributes. SystemItem may be used for any system-related item, as a catch-all. It may contain plain text, FunctionParam, VarParam, Anchor, and Optional, and has common and HasRefEntry attributes. SystemName is the name of any system. It may contain plain text only, and has common and HasRefEntry attributes. Table is an array of text. A Table may have a Title, TitleAbbrev, and Graphic; following those elements it may have a TableSpec (containing such things as troff formatting information), any number of TableColHeads (containing headings for the columns of the Table), and one or more TableRows of TableCells. Table has common and Number attributes. TableCell is a part of a TableRow in a Table. It may contain in-line elements and has common attributes. TableColHead is an optional part of Table, containing headings for the columns of the Table as TableCells. It has common attributes. TableRow is part of Table. A Table has TableRows of TableCells. It has common attributes. TableSpec tags formatting information for a Table; it is not the text of a Table's heading. It may contain in-line elements and has common attributes. Task is any set of Paras and lists that instructs the reader how to perform a given task. Task may have a Title and TitleAbbrev, and has common attributes. Term is the hanging term attached to a ListItem within a VarListEntry in a VariableList; visually, a VariableList is a set of Terms with attached items such as paragraphs. Each ListItem may be associated with a set of Terms. Term may contain in-line elements or Synopsis, and has common and HasRefEntry attributes. Tertiary is a word or phrase that is to appear in the index under a Secondary entry. It must be nested within IndexTerm tags and must follow a Secondary element. Tertiary may contain in-line elements, and has common and HasRefEntry attributes. TertiaryIE is part of IndexEntry, like PrimaryIE, q.v. Tip is a suggestion to the user, set off from the text and supplied with a title, which is ``Tip'' unless another Title is supplied explicitly. The contents of a Tip may include Paras, lists, and so forth. Tip has common attributes. Title is a string of characters, the text of a heading or element title. It is NOT the title of a Book: that is BookTitle. Title may contain in-line elements, and has common and PageNum attributes. TitleAbbrev is an optional element of anything titled. You may want to employ this element when a title is so long that you fear it will be truncated in some element of an online display, such as a title bar. TitleAbbrev may contain in-line elements, and has common attributes. ToC is a Table of Contents, which may be a book component on its own or may occur within other book components. It may have a DocInfo, Title, and TitleAbbrev, and contains ToCentry1s. ToC has common attributes. ToCentry1 is the top-level tag for items in a ToC. In the manner of Sect1, it may contain subsidiary groups (e.g., for headings and subheadings within a chapter), named ToCentry2--5. ToCentry1--5s have common attributes and a PageNum attribute, for indicating the page numbers on which the ToCentries appear in a print book. ToCentry1--5 may contain in-line elements. Token is a unit of information in the context of lexical analysis. Token contains plain text and has common and HasRefEntry attributes. Type indicates the classification of a value. Type contains plain text and has common and HasRefEntry attributes. UserInput is an in-line element used to tag data entered by the user. You might use this element most frequently in LiteralLayouts and Screens. UserInput may contain in-line elements, and has common and HasRefEntry attributes. VariableList is a list of VarListEntries, which are composed of sets of one or more Terms with associated ListItems, which contain Paras. Inclusions are as for OrderedList, q.v. VariableList has common attributes. VarListEntry is a component of VariableList, q.v. VarParam tags any character string that is to be replaced by a real name or value by the user. In ``cat filename,'' filename is a VarParam. If a VarParam is also, say, a Command, nest the VarParam tags within the Command tags: VarParam may contain only plain text, Superscript, and Subscript, not in-line elements. It has common attributes. VolumeNumber is the number of a Book in relation to a set or Set. It contains plain text and has common attributes. Warning is an admonition set off from the text and supplied with a title, which is ``Warning'' unless another Title is supplied explicitly. The contents of a Warning may include Paras, lists, and so forth. Warning has common attributes. WordAsWord is supplied for use when a word (or letter or number) is used not to represent the thing or idea it usually represents, but merely as the word itself. For example, ``The term <WORDASWORD>Gothic</WORDASWORD> means different things to art historians and typographers,'' or for a single character, ``the letter <WORDASWORD>X</WORDASWORD>''. WordAsWord may contain only plain text, and has common attributes. XRef is a cross reference link to another part of the document, such as a Table, Figure, or Example. An XRef may contain text or be empty; it has an Endterm attribute, the value of which may be set to the ID of the text to appear in the cross reference if no content is supplied. An XRef that has both content and an Endterm attribute is faulty. XRef also has a Linkend attribute, the value of which is the ID of the target of the XRef. Year is part of DocInfo and BiblioEntry (year of publication of the book). Year may contain only plain text, and has common attributes.