id
Document Internal Identifier
Unique internal identifier of an element; allows element to be cross-referenced (made into a link). Value must be unique across a document, not just for an element type.
Remarks
The ID and IDREF attribute values constitute a primitive reference
mechanism for XML that allows internal linking, for example, from a reference in the text to a figure or a table. As another 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-ref> element, so that the full glyph data can be pointed to and need not be repeated every time the character is used.
An identifier string is typically 1-32 characters in length and must start with a letter of the alphabet. (It is an XML rule that identifiers may not start with a digit.)
External Identifiers: This attribute holds an internal document identifier that can be used by software to
perform a simple link. It should not be confused with elements such as <contrib-id>
or <institution-id> that are used to hold externally
defined identifiers such as an ORCID personal identifier (for the contributor id), or a Ringgold identifier (for an institution id).
Used on Element: <target>
| Value | Meaning |
|---|---|
| An XML identifier (ID) | A unique identifier for the element. An XML parser can verify that an IDREF-style attribute pointing to one of these is pointing to a valid ID. |
| Restriction | This attribute is required; it must be provided if the element is used. |
Used on these Elements:
<abbrev>, <abstract>, <access-date>, <ack>, <accrediting-organization>, <addr-line>, <address>, <adoption>, <aff>, <aff-alternatives>, <ali:free_to_read>, <ali:license_ref>, <alt-text>, <alt-title>, <alternatives>, <annotation>, <anonymous>, <app>, <app-group>, <array>, <article-title>, <attrib>, <author-comment>, <authorization>, <award-id>, <back>, <bio>, <body>, <bold>, <boxed-text>, <break>, <caption>, <chapter-title>, <chem-struct>, <chem-struct-wrap>, <citation-alternatives>, <city>, <code>, <col>, <colgroup>, <collab>, <collab-alternatives>, <comm-ref>, <comm-ref-group>, <comment>, <compl>, <compl-title-wrap>, <compound-kwd>, <compound-kwd-part>, <compound-subject>, <compound-subject-part>, <conf-acronym>, <conf-date>, <conf-loc>, <conf-name>, <conf-sponsor>, <content-language>, <contrib>, <contrib-group>, <contrib-id>, <copyright-holder>, <copyright-statement>, <copyright-year>, <count>, <country>, <counts>, <custom-meta>, <custom-meta-group>, <data-title>, <date>, <date-in-citation>, <day>, <def>, <def-head>, <def-item>, <def-list>, <degrees>, <disp-formula>, <disp-formula-group>, <disp-quote>, <doc-ident>, <doc-number>, <doc-ref>, <doc-type>, <editing-instruction>, <edition>, <element-citation>, <elocation-id>, <email>, <equation-count>, <era>, <etal>, <ext-link>, <fax>, <fig>, <fig-count>, <fig-group>, <fixed-case>, <fn>, <fn-group>, <fpage>, <full>, <funding-source>, <given-names>, <glossary>, <glyph-data>, <glyph-ref>, <gov>, <graphic>, <hr>, <ics>, <ics-desc>, <ics-wrap>, <index>, <index-div>, <index-entry>, <index-group>, <index-term>, <index-term-range-end>, <index-title-group>, <inline-formula>, <inline-graphic>, <inline-supplementary-material>, <institution>, <institution-id>, <institution-wrap>, <intro>, <intro-title-wrap>, <is-proof>, <isbn>, <iso-meta>, <issn>, <issn-l>, <issue>, <issue-id>, <issue-part>, <issue-title>, <italic>, <journal-id>, <kwd>, <kwd-group>, <label>, <language>, <license>, <license-p>, <list>, <list-item>, <long-desc>, <lpage>, <main>, <main-title-wrap>, <media>, <meta-date>, <meta-name>, <meta-note>, <meta-value>, <milestone-end>, <milestone-start>, <mixed-citation>, <monospace>, <month>, <name>, <name-alternatives>, <named-content>, <nat-meta>, <nav-pointer>, <nav-pointer-group>, <nested-kwd>, <nlm-citation>, <non-normative-example>, <non-normative-note>, <normative-example>, <normative-note>, <notes>, <notes-group>, <num>, <object-id>, <on-behalf-of>, <open-access>, <originator>, <overline>, <p>, <page-count>, <page-range>, <part-number>, <part-of-speech>, <part-title>, <patent>, <permissions>, <person-group>, <phone>, <postal-code>, <prefix>, <preformat>, <price>, <private-char>, <proj-id>, <pronunciation>, <pub-date>, <pub-id>, <publisher-loc>, <publisher-name>, <rb>, <ref>, <ref-count>, <ref-list>, <reg-meta>, <related-article>, <related-object>, <related-term>, <release-date>, <release-version>, <release-version-id>, <role>, <roman>, <rt>, <ruby>, <sans-serif>, <sc>, <sdo>, <season>, <sec>, <secretariat>, <see>, <see-also>, <see-also-entry>, <see-entry>, <self-uri>, <series>, <sig>, <sig-block>, <size>, <source>, <speaker>, <speech>, <standard>, <state>, <statement>, <std>, <std-doc-meta>, <std-id>, <std-id-group>, <std-ident>, <std-meta>, <std-org>, <std-org-abbrev>, <std-org-group>, <std-org-name>, <std-ref>, <std-xref>, <strike>, <string-name>, <styled-content>, <sub>, <sub-part>, <subj-group>, <subject>, <subtitle>, <suffix>, <sup>, <suppl-number>, <suppl-type>, <suppl-version>, <supplement>, <supplementary-material>, <surname>, <table>, <table-count>, <table-wrap>, <table-wrap-foot>, <table-wrap-group>, <tbody>, <td>, <term>, <term-display>, <term-head>, <term-sec>, <term-source>, <tex-math>, <textual-form>, <tfoot>, <th>, <thead>, <time-stamp>, <title>, <title-wrap>, <toc>, <toc-div>, <toc-entry>, <toc-group>, <toc-title-group>, <tr>, <trans-source>, <trans-subtitle>, <trans-title>, <trans-title-group>, <underline>, <uri>, <urn>, <verse-group>, <verse-line>, <version>, <volume>, <volume-id>, <volume-series>, <wi-number>, <word-count>, <xref>, <year>
| Value | Meaning |
|---|---|
| An XML identifier (ID) | A unique identifier for the element. An XML parser can verify that an IDREF-style attribute pointing to one of these is pointing to a valid ID. |
| Restriction | This is an optional attribute; there is no default. |
Example 1
... <sec id="s6.7.1.5"> <label>6.7.1.5</label> <title>Ambient illumination</title> <p>This test is used to determine the ambient light levels under which the scanner will operate.</p> <p>... Specific applications may not require the extended range noted in <xref ref-type="table" rid="t11">Table 11</xref>.</p> <table-wrap id="t11"> <label>Table 11</label> <caption><title>Ambient illumination levels</title></caption> <table> <thead> <tr> <th>Lighting Conditions</th> <th>Illumination Level Lux</th> </tr> </thead> <tbody> <tr> <td>Dark room</td> <td>0</td> </tr> <tr> <td>Desk top</td> <td>100</td> </tr> <tr> <td>Overcast daylight</td> <td>1,000</td> </tr> <tr> <td>Bright sunlight</td> <td>100,000</td> </tr> </tbody> </table> </table-wrap> ... </sec> ...
Example 2
... <sec id="s5_1"> <label>5.1</label> <title>Two approaches to addressing accessibility in standards</title> ... <p><xref ref-type="fig" rid="f1">Figure 1</xref> provides a graphical summary of how this Guide can be used.</p> <fig id="f1" orientation="portrait" position="anchor"> <label>Figure 1</label> <caption> <title>Two approaches to address accessibility in standards</title> </caption> <graphic xlink:href="g3658.jpg"/> </fig> ... </sec> ...