It may indicate the quantity and frequency of the accruals.  Optional. Repeatable. (EX 1, 2, 3)

Frequency of Use (англ.) A measure of reference activity usually expressed as a ratio of a number of retrievals to time period, or bygeneral terms such as active or inactive this subfiield indicates the measure of reference activity, usuallyexpressed as a ratio of a number of retrievals to time period, or by general terms such as active or inactive. Optional. Repeatable. (EX 2)

Institution to which the Field Applies (англ.) Name of the institution to which field applies in the coded form if it is considered necessary by the agencywhich creates the record to identify specific attributes of an item. If the subfield is used codes should be entered in accordance with the provisions of International StandardIdentifier for Libraries and Related Organizations (ISIL), ISO 15511 or may contain codes from MARCCode List for Organizations, otherwise, the full name of the agency or a national code may be used. If the institution holds more than one copy the shelfmark of the item should be added after a colon.  Notrepeatable.

Materials Specified (англ.) Part of the described materials to which the field applies.  Not repeatable. (EX 3)