TEI and Topic Maps

Constituents of a Topic Map

All things in the world, anything conceivable, is a 'subject' .
In Topic Maps, a 'topic' works as a proxy for a subject. In other words, a topic reifies a subject.
Topics can have a 'name' .
Topics can be placed in a 'scope' , which governs the extend of their validity.
Topics are connected through 'associations' .
Topics can have 'occurrences' .
A XML Topic Map can contain a 'mergeMap' element to include other Topic Maps.

Note: The element names and syntax differ considerably between SGML and XML Topic Maps, given here are those for XML, which probably will see more widespread use.