subjectterm — A term in a group of terms describing the subject matter of a document
SubjectTerm is an individual subject word or phrase that
describes the subject matter of a document or the portion of a
document in which it occurs.
Subject terms are not expected to contain any markup. They are external descriptions from a controlled vocabulary.
May be formatted inline or as a displayed block, depending on context. Subject terms are rarely displayed to a reader. Usually, they are reserved for searching and retrieval purposes.