The number and any prefix word associated with, for example, the title or the caption of a <fig>, such as “Figure 3.” or “Exhibit 2.”. This element is also used for the number or symbol used as a prefix character for a footnote and placed at the place of the footnote reference.
This element can be used to preserve the prefix number or label of an element, for example, for a reference or citation “25.” or “[Lapeyre 2002]”. This can be useful when reconstructing untagged cross references.
<!ELEMENT label (#PCDATA %label-elements;)* >
Any combination of:
<abstract> Abstract; <ack> Acknowledgments; <aff> Affiliation; <app> Appendix; <array> Array (Simple Tabular Array); <author-notes> Author Note Group; <boxed-text> Boxed Text; <chem-struct> Chemical Structure (Display); <chem-struct-wrapper> Chemical Structure Wrapper; <citation> Citation; <corresp> Correspondence Information; <def-item> Definition List: Definition Item; <def-list> Definition List; <disp-formula> Formula, Display; <fig> Figure; <fig-group> Figure Group; <fn> Footnote; <graphic> Graphic; <list> List; <list-item> List Item; <media> Media Object; <note> Note in a Reference List; <notes> Notes; <ref> Reference Item; <sec> Section; <statement> Statement, Formal; <supplementary-material> Supplementary Material; <table-wrap> Table Wrapper; <table-wrap-group> Table Wrapper Group; <trans-abstract> Translated Abstract
In a figure:
...<ref-list>
<title>References</title>
<ref id="bid.41">
<label>1</label>
<citation>
<person-group>
<name><surname>Olson</surname><given-names>M</given-names></name>
...
</person-group>
<article-title>A common language for physical mapping
of the human genome</article-title>
<source>Science</source>
<year>1989</year>
<volume>245</volume>
<issue>4925</issue>
<fpage>1434</fpage>
<lpage>1435</lpage>
<pub-id pub-id-type="pmid">2781285</pub-id>
</citation>
</ref>
</ref-list>...
In a bibliographic reference:
...
<book-part id="bid.2" book-part-type="chapter" book-part-number="1">
<book-part-meta>...</book-part-meta>
<body>
<sec id="bid.3">
<title>History</title>
<p>Initially, GenBank was built and maintained at Los Alamos
National Laboratory ...</p>
</sec>
...
</body>
<back>
<ref-list>
<title>References</title>
<ref id="bid.41">
<label>1</label>
<citation>
<person-group>
<name><surname>Olson</surname>
<given-names>M</given-names></name>
<name><surname>Hood</surname>
<given-names>L</given-names></name>
<name><surname>Cantor</surname>
<given-names>C</given-names></name>
<name><surname>Botstein</surname>
<given-names>D</given-names></name>
</person-group>
<article-title>A common language for physical mapping
of the human genome</article-title>
<source>Science</source>
<year>1989</year>
<volume>245</volume>
<issue>4925</issue>
<fpage>1434</fpage>
<lpage>1435</lpage>
<pub-id pub-id-type="pmid">2781285</pub-id>
</citation>
</ref>
</ref-list>
</back>
</book-part>
...
common.ent