<label>

Label (of an Equation, Figure, Reference, etc.)

Number and/or prefix word placed at the beginning of display elements (for example, equation, statement, figure).

Remarks

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>

Attributes

Content Model

<!ELEMENT  label        (#PCDATA %label-elements;)*                  >

Expanded Content Model

(#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 | inline-media | private-char | chem-struct | inline-formula | tex-math | mml:math | abbrev | index-term | index-term-range-end | milestone-end | milestone-start | named-content | styled-content | fn | target | xref | sub | sup | x | break)*

Description

This element may be contained in:

Example 1

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>
...

Example 2

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 &#x03C7;<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 specific-use="online" xlink:href="1.4821168.figures.online.f3.jpg"/>
</alternatives>
</fig>
...

Example 3

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>
...

Example 4

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>
...

Example 5

In a mixed-style bibliographic reference (punctuation and spacing preserved):
<article dtd-version="1.2">
<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>

Example 6

For a hypothesis:
<article dtd-version="1.2">
<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>