In element <target>, this attribute must be used if the element is used.
| Value |
Meaning |
| An XML identifier (ID) |
A unique identifier for the element. XML parsers can verify that an element pointing
to one of these is pointing to a valid ID. |
In elements <abbrev>, <abstract>, <access-date>, <ack>, <addr-line>, <address>, <aff>, <aff-alternatives>, <ali:free_to_read>, <ali:license_ref>, <alt-text>, <alternatives>, <annotation>, <anonymous>, <app>, <app-group>, <article>, <article-meta>, <article-title>, <attrib>, <author-comment>, <award-group>, <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>, <comment>, <compound-kwd>, <compound-kwd-part>, <conf-acronym>, <conf-date>, <conf-loc>, <conf-name>, <conf-num>, <conf-sponsor>, <conf-theme>, <conference>, <contrib>, <contrib-group>, <contrib-id>, <copyright-holder>, <copyright-statement>, <copyright-year>, <country>, <data-title>, <date>, <date-in-citation>, <day>, <def>, <def-head>, <def-item>, <def-list>, <degrees>, <disp-formula>, <disp-formula-group>, <disp-quote>, <edition>, <element-citation>, <elocation-id>, <email>, <era>, <etal>, <ext-link>, <fax>, <fig>, <fixed-case>, <fn>, <fn-group>, <fpage>, <front>, <funding-group>, <funding-source>, <funding-statement>, <given-names>, <glossary>, <glyph-data>, <glyph-ref>, <gov>, <graphic>, <hr>, <inline-formula>, <inline-graphic>, <inline-supplementary-material>, <institution>, <institution-id>, <institution-wrap>, <isbn>, <issn>, <issn-l>, <issue>, <issue-id>, <issue-part>, <issue-title>, <italic>, <journal-id>, <kwd>, <kwd-group>, <label>, <license>, <license-p>, <list>, <list-item>, <long-desc>, <lpage>, <media>, <mixed-citation>, <monospace>, <month>, <name>, <name-alternatives>, <named-content>, <nested-kwd>, <nlm-citation>, <object-id>, <on-behalf-of>, <open-access>, <overline>, <p>, <page-count>, <page-range>, <part-title>, <patent>, <permissions>, <person-group>, <phone>, <postal-code>, <prefix>, <preformat>, <price>, <principal-award-recipient>, <principal-investigator>, <private-char>, <product>, <pub-id>, <publisher-loc>, <publisher-name>, <rb>, <ref>, <ref-list>, <related-article>, <related-object>, <role>, <roman>, <rt>, <ruby>, <sans-serif>, <sc>, <season>, <sec>, <self-uri>, <series>, <size>, <source>, <speaker>, <speech>, <state>, <statement>, <std>, <std-organization>, <strike>, <string-name>, <styled-content>, <sub>, <subtitle>, <suffix>, <sup>, <supplement>, <supplementary-material>, <surname>, <table>, <table-wrap>, <table-wrap-foot>, <tbody>, <td>, <term>, <term-head>, <textual-form>, <tfoot>, <th>, <thead>, <time-stamp>, <title>, <title-group>, <tr>, <trans-source>, <trans-title>, <underline>, <uri>, <verse-group>, <verse-line>, <version>, <volume>, <volume-id>, <volume-series>, <xref>, and <year>, this attribute may be used if the element is used.
| Value |
Meaning |
| An XML identifier (ID) |
A unique identifier for the element. XML parsers can verify that an element pointing
to one of these is pointing to a valid ID. |