id

Identifier

Definition

Indicates the unique identifier for an associated element, so that the element’s content may be cross-referenced.

Usage

For example, when an id attribute has been used on a <glyph-data> element, that identifier can be referenced by an IDREF-style attribute on a Glyph Reference for a Private Character element, so that the full glyph data need not be repeated every time the character is used.

Remarks

The uniqueness of an identifier is not maintained by the XML; thus, a naming convention should be adopted. This identifier will be referenced by other elements; therefore, it is essential that no logical conflicts occur within a single XML file. An identifier string is typically 1-32 characters in length and starts with a letter of the alphabet. (It is an XML rule that identifiers may not start with a digit.)

Attribute Values

In Elements

<ack> Acknowledgments
<address> Address/Contact Information
<aff> Affiliation
<alt-text> Alternate Title Text (For a Figure, Etc.)
<app> Appendix
<array> Array (Simple Tabular Array)
<author-notes> Author Note Group
<bio> Biography
<boxed-text> Boxed Text
<caption> Caption of a Figure, Table, Etc.
<chem-struct> Chemical Structure (Display)
<chem-struct-wrapper> Chemical Structure Wrapper
<citation> Citation
<col> Table Column (XHTML table model)
<colgroup> Table Column Group (XHTML table model)
<collab> Collaborative (Group) Author
<contrib> Contributor
<corresp> Correspondence Information
<def> Definition List: Definition
<def-item> Definition List: Definition Item
<disp-formula> Formula, Display
<disp-quote> Quote, Displayed
<ext-link> External Link
<fig> Figure
<fig-group> Figure Group
<fn> Footnote
<glossary> Glossary Elements List
<glyph-data> Glyph Data for a Private Character
<graphic> Graphic
<inline-formula> Formula, Inline
<inline-graphic> Graphic, Inline
<inline-supplementary-material> Inline Supplementary Material
<institution> Institution Name: in an Address
<kwd> Keyword
<kwd-group> Keyword Group
<long-desc> Long Description
<media> Media Object
<mml:math> Math (MathML 2.0 DTD)
<named-content> Named Special (Subject) Content
<nlm-citation> NLM Citation Model
<note> Note in a Reference List
<notes> Notes
<p> Paragraph
<preformat> Preformatted Text
<ref> Reference Item
<sec> Section
<speech> Speech
<statement> Statement, Formal
<supplementary-material> Supplementary Material
<table> Table (XHTML table model)
<table-wrap> Table Wrapper
<table-wrap-group> Table Wrapper Group
<target> Target of an Internal Link
<tbody> Table Body (XHTML table model)
<td> Table Data Cell (XHTML table model)
<term> Definition List: Term
<tfoot> Table Footer (XHTML table model)
<th> Table Header Cell (XHTML table model)
<thead> Table Header (XHTML table model)
<tr> Table Row (XHTML table model)
<verse-group> Verse Form for Poetry
<xref> X(cross) Reference
Value Meaning
An identifier (ID) A unique identifier for the element. This can be used by an IDREF-style attribute on, for example, a cross-reference <xref> element, to point to the element that has this ID.
Restriction: This attribute may be specified if the element is used.

In Elements

<def-list> Definition List
<list> List
<list-item> List Item
<tex-math> Tex Math Equation
Value Meaning
Data characters Text, numbers, or special characters.
Restriction: This attribute may be specified if the element is used.