TEI allows texts to be treated individually as “unitary texts” or to be aggregated into groups, or “composite texts”. Composite texts contain groupings of <text> elements, which themselves may contain further groupings.
For a single unitary text this is the basic encoding structure:
<TEI.2>
<teiHeader>
</teiHeader>
<text>
<front></front>
<body>
...
</body>
<back></back>
</text>
</TEI.2>
For a composite text the <group> element replaces <body>. There can be front and back matter for the entire text (for instance, an index to all of the works included in the collection) as well as front/back matter for the individual texts within the group:
<TEI.2>
<teiHeader>
</teiHeader>
<text>
<front>Optional front matter for entire grouping</front>
<group>
<text><front></front><body></body><back></back></text>
<text><front></front><body></body><back></back></text>
[...more texts...]
</group>
<back>Optional back matter for entire grouping</back>
</text>
</TEI.2>