Recently both discussion and controversy have sparked around the notion of assigning a separate ISBN (International Standard Book Number) for electronic publications. Some have suggested there should be a separate number for each kind of electronic format in which a book is distributed, that is, for example, separate numbers for Kindle, Sony Reader, and pdf editions. And some suggest just one distinct number for all electronic editions of a book is adequate, while others believe there is no need for a distinguishing assignment beyond the book's original ISBN.  To understand how to approach this question, it is good to review the purpose and history of ISBN numbers.

The ISBN is a way of organizing the commerce of the book publishing industry which has been suggested for more than forty years by the ISO (International Organization for Standardization). This non-governmental group, based in Geneva, Switzerland, consists of 163 member countries that come together to create standards for business, government, and society with the goal of creating more efficient ways of working internationally. All compliance to ISO standards is voluntary. There are no laws involved. However the ISBN (managed by the Bowker Company) has been an extremely successful method for tracking books internationally since its inception and is widely used. The notion that different formats of books should have different ISBNs is not a new concept. In fact, the idea goes back to the 1970 ISO consensus that each book format should have a distinct ISBN assigned, and specifically in 2005 the ISO addressed the electronic editions of books as separate formats requiring separate numbers.

There are a number of reasons why distinct ISBNs make sense for e-books. Mostly, however, it is helpful to publishers to be able to track sales data and royalty information and helpful to customers, such as libraries, to be able to see at a glance if more than one format of a book is available for ordering. Third parties can assign ISBNs for their convenience. A wholesaler, for example, can assign a number to a book that does not have one. Nevertheless it is important to remember that ISBN has nothing to do with copyright ownership. That is a separate matter.

At Dorrance Publishing, we now assign a distinct e-book ISBN for each book we publish. In keeping with ISO recommendations, we do not assign a separate number for each kind of electronic publishing format, just one number for all electronic formats in which a book has been made available.