Instructions:

Theme: subjects covered by the data set (for a list of some commonly-used thesauri, see Part IV: Subject/index term
          sources in Network Development and MARC Standards Office, 1988, USMARC code list for relators, sources,
          and description conventions: Washington, Library of Congress).

Place: geographic locations characterized by the data set.

Stratum: layered, vertical locations characterized by the data set.

Temporal: time period(s) characterized by the data set.