Section whose content is typically a list of terms and definitions, usually tagged as one or more two-part lists called <def-list>. Typically part of the back matter of a document.
The model for <glossary> is deliberately broad in order to accommodate glossaries that are tabular, heavily annotated, constructed as a series of notes, or otherwise unusually constructed.
Glossaries are recursive with various levels indicated by containment, not by different names for the embedded glossaries. A typical simple <glossary> may contain only a title and a <def-list>. A more complex <glossary> may be divided into several different lists of terms, each headed by a title that describes the audience for the particular terms. These glossaries inside a glossary are tagged using the <glossary> element rather than a different, explicitly named element such as a <sub-glossary> or <glossary-sec>.
<!ELEMENT glossary %glossary-model; >
(label?, title?, (address | alternatives | answer | answer-set | array | boxed-text | chem-struct-wrap | code | fig | fig-group | graphic | media | preformat | question | question-wrap | supplementary-material | table-wrap | table-wrap-group | disp-formula | disp-formula-group | def-list | list | tex-math | mml:math | p | related-article | related-object | ack | disp-quote | speech | statement | verse-group | x)*, glossary*)
The following, in order:
<abstract>, <ack>, <answer>, <app>, <back>, <bio>, <book-back>, <book-part-wrapper>, <boxed-text>, <front-matter>, <glossary>, <notes>, <question>, <sec>, <trans-abstract>
...
<book-back>
<glossary id="bid.1237">
<title>Glossary</title>
<def-list>
<def-item>
<term id="bid.1238">3-D or 3D</term>
<def><p>Three-dimensional.</p></def>
</def-item>
<def-item>
<term id="bid.1722">Accession number</term>
<def><p>An Accession number is a unique identifier
given to a sequence when it is submitted to one of the
DNA repositories (GenBank, EMBL, DDBJ). The initial
deposition of a sequence record is referred to as version
1. If the sequence is updated, the version number is
incremented, but the Accession number will remain
constant.</p></def>
</def-item>
...
</def-list>
</glossary>
</book-back>
...