ISIL and library codes are used to identify libraries and related organisations (e.g. archives and museums) in network catalogues, interlibrary loan and other applications used by information technology. In this context ISIL has gained an important role for reason of its use as an identifier in RFID-technology, machine readable data, the common authority file (GND) and MARC 21 data.
Assignment is carried out on application by the German ISIL- and Library Code Agency at the Staatsbibliothek zu Berlin.