Demographic Groups” is a bilingual, hierarchical vocabulary that defines communities of individuals based on shared characteristics such as age, educational level, profession, and field of activity. The vocabulary is applied to suggest audience groups or user communities for which a resource may be relevant or appropriate. It is also used to categorize persons in authority files according to demographic attributes. The demographic groups are linked, through equivalence or associative relationships, to terms from the corresponding vocabulary of the Library of Congress and other open vocabularies.