What exactly does an ISBN record?
Thirteen digits carry a book's identity. This piece looks at what is inside the barcode and why it does not change with every printing.
The barcode on the back cover of a book is not a random number. Every part of the thirteen digits says something.
What the digits mean
The first three digits show the product type, the next group the country or language region, the section after that the publisher, and the last section that publisher's own book. The final digit is a check digit: it is calculated from the other twelve and catches misreads.
When it changes
An ISBN is given not to a work but to a particular edition of that work. The hardback and paperback of the same book take different numbers; a second printing keeps the same number. This distinction is critical for stock and sales data to match correctly.
Why it matters in the record
Every record in Kibo Catalogue is built on this number. A number whose check digit does not hold does not enter the system; because records are unique, the same number cannot be attached to two different books.
