ISSN

ISSN stands for International Standard Serial Number. It is an eight-digit code used to uniquely identify serial publications such as journals, magazines, newspapers, and annuals. An ISSN identifies the title of a serial independent of its publisher, language, or country, and it is widely used in libraries, catalogs, and bibliographic databases to facilitate cataloging, ordering, and linking across formats.

The code is typically written as four digits, a hyphen, four digits (for a total of eight characters). The final character is a check digit that can be a digit or the letter X. The check digit is calculated from the first seven digits using a modulo 11 algorithm with weights 8 through 2; if the result is 10, the check digit is X, and if the result is 11, the check digit is 0. Print and electronic versions of a title are assigned separate ISSNs (often denoted ISSN for the print edition and E-ISSN for the electronic edition).

Administration of the ISSN system is coordinated by the ISSN International Centre in Paris, with national centers responsible for assigning ISSNs to publications in their jurisdictions. The system uses a title-based identifier, and different media versions of the same title may receive distinct ISSNs. In addition, the ISSN system includes the ISSN-L (linking ISSN), which provides a single identifier to link all media versions of a serial for linking and metadata aggregation purposes.

ISSNs are widely used in libraries, publishers, indexing services, and databases to improve discovery, management, and cross-format linking of serial publications.