The International Standard Book Number (ISBN) has been invented for more than 30 years. It has experienced exponential growth and remarkable success. Today, every book, magazine, cassette and CD bear an ISBN number. Every item to be sold in bookstore is required to furnish an ISBN. The ISBN is used extensively by publishers, retailers as wells as libraries to manage inventory. The ISBN is represented through an EAN barcode, a.k.a. Bookland barcode plus an optional 5-digit (2-digit for magazines) add-on.

An ISBN is a 10 digit number preceded by the letters ISBN. The text is usually printed with OCR-A font. The 10-digit number is divided into four parts of variable length, which are separated by hyphens or spaces. The four parts are Group Identifier, Publisher Identifier, Title Identifier and Check Digit respectively. Note that the length of each part is not fixed, though the total length must be 10.

A Bookland symbol may have an optional 2-digit or 5-digit add-on symbol. To add the supplement, add them at the end of the main message and separate the two parts with a vertical bar(|), in the same way as the UPC and EAN supplements. For example, to encode an ISBN number 0-201-61595-9 with pricing information 53995, set the Message property to 0-201-61595-9|53995.

Note on 13-digit ISBN

Beginning on January 1, 2007, all 10-digit ISBNs are required to be re-expressed as a 13-digit number (EAN-13). To convert a 10-digit ISBN to 13-digit EAN number, drop the last checksum digit of the 10-digit ISBN number and add prefix 978 at the beginning. Calculate the EAN-13 check digit based on the result and append this checksum digit to the end of the result. To create the barcode, use EAN13 symbology instead and assign the 13-digit ISBN number to the message property.