What is the ISBN?
The International Standard Book Number or ISBN is a unique identifier for all commercial publications. It can usually be found on the page with the publishing details, but is also given with the bar code and sometimes on the spine.
It’s used as a unique reference for book listings to facilitate easy ordering, searching and cataloguing of publications. For most individual buyers, the ISBN is useful for distinguishing an exact book particularly where confusion of titles is a possibility. Over recent years it’s also come into its own with online ordering systems, as a precise edition can be identified without having view of the book itself.
A fresh ISBN is assigned to each edition and for every change made, besides reprints, of a work. It’s not quite universal as some small private printers may not apply one, or where an author has not followed the recognised procedure it may also be absent.
Today the ISBN is not used for printed works alone as it’s also assigned to electronic publications. This has necessitated changes due to the sudden rise in the number of publications with the boom in self-publication of eBooks, so from the start of 2007 the ISBN has been thirteen characters in length, whereas prior to that it was just ten. The exact method of allocating the number varies from country to country.
How did it come about?
The ISBN number can trace its origins back to the Standard Book Numbering system of 1966. This was drawn up by the British Publishers Association’s Distribution and Methods Committee at the instigation of the book retailer W H Smith.
The following year the International Organisation for Standardisation set up a working group to adapt the British system for international use, and the ISBN number was approved and published as the International Standard ISO2108 in 1970.
The UK continued to use its initial nine-digit code for several years but this can be converted to the ten digits by prefixing it with a 0. The ISBN remains based in London to this day.
Changes to the system
Anticipating a shortage of available numbers for certain categories of publication, the ISO opted to change the number length from ten digits to thirteen, and this was undertaken between 2005 and 2007 by the introduction of a prefix number. As need arises further prefix numbers will be made available ensuring the long-term viability of the system.
How it’s allocated
A modern thirteen digit ISBN has a prefix allocated by GS1. GS1 is an international body working with local organisations in more than 110 countries to allocate and disseminate identification numbers across a range of fields including ISBN and bar codes. So far the numbers 978 and 979 have been made available for use as ISBN prefixes.
The next number represents a language group or country identifier. This is called the registration group element. Those allocated to English speaking countries with the 978 prefix are ‘0’ and ‘1,’ French is ‘2,’ German ‘3,’ etc. This element can be up to five digits in length for less widely spoken languages, but the most widespread language groups are just one or two digits in length so as to provide more characters for other parts of the code. A different system is used with the 979 prefix, but much of this series is currently reserved for musical publications.
This is followed by the registrant element, a number assigned from a range given to the publisher who then allocates one to each of the books they produce. They also allocate the publication element that follows it, which is taken from a block of numbers assigned to each publisher. Large publishers will receive blocks of ISBNs according to their anticipated need and they will receive further blocks as those they have are exhausted. Variable block lengths can be supplied for publishers dealing with different language publications for which the registration group element might vary in length.
The final digit of the number is a check digit for error detection.
Often the ISBN is separated into its constituent parts with hyphens or spaces, but is also sometimes shown as a single string of thirteen digits.