The term enumeration is used here to signify a standard that is used to define the meaning of a vocabulary used by the security community. That vocabulary is generally either a set of (a) global identifiers for shared data objects that need to be referenced in a common way, or (b) data labels that need to be clearly defined. Some of the standards specify such vocabularies directly, while others provide guidelines for the creation of enumerations for a particular domain but do not actually enumerate the vocabulary.