The ISIL implementation runs in the Republic of Belarus. The International Standard Identifier for Libraries and Related Organisations (ISIL), ISO 15511, assigns unique identifiers to libraries and related organisations, such as archives and museums.
An ISIL-code is alphanumeric, with a maximum of 16 characters. Valid symbols are A-Z, 0-9, solidus, hyphen-minus and colon. An ISIL consists of a prefix identifying the authority which issued the ISIL, a dash, and then an identifier issued by that authority. All two letter prefixes are reserved for the country code, followed by an identifier assigned by that country's national library authority, for example BY-HM0001. If the ISIL code is written, printed or visually represented in a different way, it must be preceded by the letters ISIL, separated from the identifier by a space: ISIL BY-HM0001.
Use of the ISIL-code allows:
establishment of links with publishers and their suppliers at the national and international levels;
issuance / receipt of documents for temporary use by Interlibrary Loan and International Interlibrary Loan;
participation in the formation of national and international catalogs;
subscriptions to library sources.
ISIL code can be assigned to any library or organization that is involved or intends to enter the international library exchange system or international book trade. The assigned ISIL-code will contain the identification of the organization.
Danish Agency for Libraries and Media provides international registering and supporting ISIL. Its role is to promote and control the use of ISIL-codes, information support of national agencies for registration and ISIL-codes support. In the Republic of Belarus, the National Library of Belarus registered as the National Agency of ISIL-codes of Belarus in December 2009 assigns and administers the ISIL code.