Four basic operations in the effective use of graphic records (documents), to store information and make it available, have been listed by Hyslop: A, recording information in documents; B, storing recorded information—documentary items; C, identifying items containing information relevant to a given problem, situation, or subject; D, providing the identified items from storage. Information storage and retrieval in the wide sense covers all these operations. In the narrow sense used in this paper, information retrieval means only C, identifying documentary items by subject.

p. 1275. - The Structure of Information Retrieval Systems (1959)