ISBN (from the English International Standard Book Number — international standard book number) is a universal identification number assigned to a book or brochure for the purpose of their identification. The ISBN is intended to identify individual books or different editions and is unique for each book edition (except reprints).
ISBN was developed in 1966 in Great Britain and adopted as an international standard ISO 2108 since 1970. Identification numbers according to this standard were ten digits long.
In 2005, the revised ISO 2108:2005 code standard was adopted, which is compatible with the EAN format and has a length of 13 digits. To convert old codes to new ones, you need to add the prefix 978, which was reserved specifically for book editions, to the 10-digit code, and recalculate the check digit according to the algorithm provided by EAN. The old (10-digit) codes are no longer supported since 2007.
The purpose of the introduction of the new format was to increase the capacity of the ISBN system (due to the introduction of the additional prefix 979) and the possibility of printing identifiers in the form of a barcode to identify publications in trade. Old 10-digit ISBN numbers are converted to 13-digit by prefixing 978 and renumbering the check digit accordingly.
To assign an ISBN number to a book, the publisher applies to the country's national agency, which is authorized to distribute ISBN blocks. The procedure for obtaining ISBN blocks is paid. After the national agency assigns a unique identifier to that publisher and issues the claimed block of numbers, the publisher may code its book products, but may not resell or share them with another publisher. The number of ISBNs issued to an individual publishing house depends on its annual output.
In Ukraine, the official representative of the international agency ISBN is the Book Chamber of Ukraine named after Ivan Fedorov.
The international standard book number consists of the abbreviation ISBN, which is written in Latin letters regardless of the language of the book's publication, and a 13-digit number (or 10 digits for editions before 2007).
A ten-digit number is divided into four parts, respectively, a 13-digit number is divided into five parts of variable length, which are separated from each other