This must have the name of a thesaurus and a term
from that thesaurus, e.g., <fclass term="autonomous region" type="administrative"/>
In this example, the thesaurus is administrativeThesaurus.xml (which starts with
<root id="administrative">, it's that root id you're matching on) and the term is
"autonomous region", which in the thesaurus looks like this:
The attribute "type" is for declaring the type of feature the individuals belong to, such as "administrative".
The attribute "term" is for declaring "county", "township", "autonomous region", etc for Administrative types of classes, or "river", "mountain", "plain" for Geophysical types, etc.