• acronymAn abbreviation composed of the first letters of a compound term or phrase; e.g. Automatic Teller Machine = ATM, United Nations = UN.
  • associative relationshipA relationship between or among terms in a controlled vocabulary that leads from one term to other terms that are related to or associated with it; begins with the words SEE ALSO or related term (RT).
  • asymmetricLacking symmetry. In the context of controlled vocabularies, reciprocal relationships are asymmetric when the relationship indicator used between a pair of linked terms is different in one direction than it is in the reverse direction, e.g. BT / NT. See also symmetric and reciprocity.
  • authority fileA set of established headings and the cross-references to be made to and from each heading, often citing the authority for the preferred form or variants. Types of authority files include name authority files and subject authority files.
  • authorizationThe process responsible for selecting terms and establishing relationships for a controlled vocabulary.
  • authorizing bodyOversight group responsible for selecting terms and establishing relationships for a controlled vocabulary.