FYI: Controlled Vocabulary

From Guidelines for the Construction, Format, and Management of Monolingual Controlled Vocabularies, ANSI/NISO Z39.19-2005
 
Controlled Vocabulary
 
A list of terms that have been enumerated explicitly. This list is controlled by and is available from a controlled vocabulary registration authority. All terms in a controlled vocabulary must have an unambiguous, non-redundant definition. Note: This is a design goal that may not be true in practice; it depends on how strict the controlled vocabulary registration authority is regarding registration of terms into a controlled vocabulary. At a minimum, the following two rules must be enforced:

1. If the same term is commonly used to mean different concepts, then its name is explicitly qualified to resolve this ambiguity. Note: This rule does not apply to synonym rings.
2. If multiple terms are used to mean the same thing, one of the terms is identified as the preferred term in the controlled vocabulary and the other terms are listed as synonyms or aliases.

Examples of controlled vocabularies are lists, synonym rings, taxonomies, and thesauri.