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 | fixed-case | italic | monospace | overline | overline-start | overline-end | roman | sans-serif | sc | strike | underline | underline-start | underline-end | ruby | 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>
For a table:
... <table-wrap id="t2" orientation="portrait" position="float"> <label>Table II.</label> <caption> <p>Models to approximate the bound frequencies as waves in X→M (<inline-graphic id="g1" xlink:href="d1"/>: Rotational, <inline-graphic id="g2" xlink:href="d2"/>: Vibrate in <italic>y</italic> direction, <inline-graphic id="g3" xlink:href="d3"/>: Vibrate in <italic>x</italic> direction, <inline-graphic id="g4" xlink:href="d4"/>: Vibrate mainly in <italic>y</italic> direction including a small portion of vibration in <italic>x</italic> direction, <inline-graphic id="g5" xlink:href="d5"/>: Vibrate mainly in <italic>x</italic> direction including a small portion of vibration in <italic>y</italic> direction).</p> </caption> <table border="1">...</table> </table-wrap> ...
For a figure:
... <sec><title>Outcome data</title> ... <p>Figure <xref ref-type="fig" rid="F2">2</xref> shows that overall there was no significant difference between day hospital and alternative forms ...</p> <fig id="F2"><label>Figure 2</label> <caption><p>Odds of death or poor outcome in patients receiving day hospital care or alternative services (random effects model). Heterogeneity between trials is presented as χ<sup>2</sup></p></caption> <graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="fors2662.f2"></graphic> </fig> </sec> ...
... <fig id="f3" position="float"> <label>FIG. 3.</label> <caption>...</caption> <alternatives> <graphic specific-use="print" xlink:href="1.4821168.figures.highres.f3.zip"></graphic> <graphic specific-use="online" xlink:href="1.4821168.figures.online.f3.jpg"></graphic> </alternatives> </fig> ...
In a note:
... <ref id="c35"> <label>35.</label> <note> <p>The geometric optimization and electronic transport properties are all calculated by a developed <italic>ab-initio</italic> software package Atomistix ToolKit, which is based on the spin-polarized density-functional theory combined with the non-equilibrium Greens functions. ...</p> </note> </ref> ...
In an element-style bibliographic reference (punctuation and spacing removed):
... <ref id="B8"><label>8</label> <element-citation publication-type="journal"> <person-group person-group-type="author"> <name><surname>Weissert</surname> <given-names>W</given-names></name> <name><surname>Wan</surname> <given-names>T</given-names></name> <name><surname>Livieratos</surname> <given-names>B</given-names></name> <name><surname>Katz</surname> <given-names>S</given-names></name> </person-group> <article-title>Effects and costs of day-care services for the chronically ill: a randomized experiment</article-title> <source>Medical Care</source> <year iso-8601-date="1980">1980</year> <volume>18</volume> <fpage>567</fpage> <lpage>584</lpage> <pub-id pub-id-type="pmid">6772889</pub-id> </element-citation> </ref> ...
In a mixed-style bibliographic reference (punctuation and spacing preserved):
<article dtd-version="1.1d1"> <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>
For a hypothesis:
<article dtd-version="1.1d1"> <front>...</front> <body> ... <p>Industrial buyers categorise foreign countries according to their level of technological achievement and subsequently differentiate their perceptions of these countries accordingly. ... The following hypothesis is posited: <statement> <label>Hypothesis 1</label> <p>Buyer preferences for companies are influenced by factors extrinsic to the firm attributable to, and determined by, country-of-origin effects.</p> </statement> </p> ... </body> <back>...</back> </article>