The Integrated Library System (ILS) is composed of bibliographic records including inventoried items, and patron records including circulation data.
The data is used in the daily operation of the library, including circulation, online public catalog, cataloging, acquisitions, collection development, processing, and serials control.
This dataset represents the usage of inventoried items by active patrons. Per the California State Library definition, San Francisco Public Library defines active patrons as a) patrons with unexpired library cards and b) patrons who had circulation activity within the last three years.