The Swiss National Library (NL) maintains the national ISIL centre for institutions from the I&D sector in Switzerland. It assigns the ISIL codes beginning with the country code prefix CH, and it maintains the register of the names and addresses of the identified institutions. The national ISIL register is held on ISplus (Archives, Libraries and Museums) in HelveticArchives.
The Danish Agency for Culture has taken the responsibility for the international co-ordination of the ISIL registration and for the maintenace of the International Standard.
ISIL stands for "International Standard Identifier for Libraries and Related Organizations" and it corresponds to International Standard ISO 15511, which came into force in September 2003.
The ISIL serves to identify libraries, archives and related institutions. With this code automated and in particular transnational library services (locating, acquisition, lending, etc.) can be simplified. The internationally valid identification number prevents misunderstandings, which could result for example from changes of name of the institutions or from language variants.
At the international and national level the ISIL takes over the function held until now at the national level by the RP/VZ acronyms of libraries and other abbreviations. Within the national interlibrary loan (ILL) of Switzerland however the RP/VZ acronyms will remain in use until further notice.