Number and/or prefix word placed at the beginning of display elements (for example, equation, statement, figure).
As an example, a label placed at the beginning of an equation (<disp-formula>) could be a number such as <label>Equation 3.</label>, <label>(3)</label>, or <label>3.</label>. A label before a statement such as a Proof or Lemma, could be a word such as <label>Proof</label> or <label>Hypothesis</label>.
Many objects can take explicit labels. For example, a <label> can contain the number or symbol used as a prefix character for a footnote that is placed at the point of the footnote reference. Similarly, the number and any prefix word associated with the title or the caption of a <fig> can be marked as a <label>, for example, “<label>Figure 3.</label>”, “<label>Exhibit 2.</label>”, or “<label>3.</label>”.
A <label> can be used to preserve the prefix number for a reference or citation “25.” or “[Lapeyre 2010]”. This can be useful when reconstructing untagged cross-references.
Accessibility: Sometimes a <label> needs to be pronounced in a way that is not reflected in its content or its tagging. The @alt attribute can be used to record the pronunciation for screen readers and other accessibility devices. For example, the element figure that follows might be pronounced as “Figure 3”.
<label alt="figure 3">Fig&#x00A0;III.</label>
<!ELEMENT label (#PCDATA %label-elements;)* >
(#PCDATA | email | ext-link | uri | inline-supplementary-material | related-article | related-object | hr | bold | italic | monospace | overline | overline-start | overline-end | roman | sans-serif | sc | strike | underline | underline-start | underline-end | alternatives | inline-graphic | private-char | chem-struct | inline-formula | tex-math | mml:math | abbrev | milestone-end | milestone-start | named-content | styled-content | fn | target | xref | sub | sup | x | break)*
Any combination of:
<abstract>, <ack>, <address>, <aff>, <app>, <app-group>, <array>, <author-notes>, <back>, <bio>, <boxed-text>, <chem-struct>, <chem-struct-wrap>, <corresp>, <def-item>, <def-list>, <disp-formula>, <disp-formula-group>, <disp-quote>, <element-citation>, <fig>, <fig-group>, <fn>, <fn-group>, <glossary>, <graphic>, <kwd-group>, <list>, <list-item>, <media>, <mixed-citation>, <note>, <notes>, <product>, <ref>, <ref-list>, <related-article>, <related-object>, <sec>, <statement>, <supplementary-material>, <table-wrap>, <table-wrap-foot>, <table-wrap-group>, <textual-form>, <trans-abstract>, <verse-group>
In a mixed-style bibliographic reference (punctuation and spacing preserved):
<article> <front>...</front> <body> ... <p>... Although there is considerable descriptive literature on day hospital care,<xref ref-type="bibr" rid="B1">1</xref> concern has been expressed that evidence for effectiveness is equivocal and that day hospital care is expensive.<xref ref-type="bibr" rid="B2">2</xref> ...</p> ... </body> <back> ... <ref-list> <ref id="B1"><label>1</label> <mixed-citation publication-type="book"> <collab>Research Unit of the Royal College of Physicians and British Geriatric Society</collab>. <source>Geriatric day hospitals: their role and guidelines for good practice</source>. <publisher-loc>London</publisher-loc>: <publisher-name>RCP</publisher-name>; <year iso-8601-date="1994">1994</year>. </mixed-citation> </ref> <ref id="B2">...</ref> ... </ref-list> ... </back> </article>