ISBNtunnuksen

ISBNtunnuksen is the Finnish term for ISBN, which stands for International Standard Book Number. It is a unique numerical identifier for books. An ISBN is assigned to each edition and variation (such as hardcover, paperback, and audiobook) of a book. The ISBN is not a substitute for a catalog record, but rather a key to that record. The system is managed by the International ISBN Agency, with national agencies responsible for assigning ISBNs within their respective countries. In Finland, the ISBN agency is part of the National Library of Finland.

The ISBN consists of ten or thirteen digits. Originally, it was a ten-digit number, but it was expanded to thirteen digits in 2007 to accommodate the growing number of publications and to align with the EAN (European Article Number) standard. The thirteen-digit ISBN is essentially a ten-digit ISBN with a 978 or 979 prefix. Each ISBN includes a prefix element, registration group element, registrant element, publication element, and a check digit. The check digit is used to detect errors in the ISBN.

ISBNs are used by booksellers, libraries, publishers, and other participants in the book industry to identify books precisely. They facilitate ordering, inventory management, and sales tracking. For example, when a bookstore needs to order a specific title, they can use its ISBN to ensure they are getting the correct edition. Libraries use ISBNs for cataloging and interlibrary loan requests. The ISBN system has been instrumental in streamlining the global book trade since its inception in the late 1960s.