мне нужен эквивалент из русской библиотечной терминологии.

в англо-английском словаре дается следующее определение:
The addition of a term to an indexing language, or the assignment of an existing descriptor to documents by an indexer, based on the frequency with which it is requested or included in the search statements entered as input by the users of an information retrieval system.

Спасибо