Even in these days when any and every aspiring writer can publish their work easily for themselves on their own website, there is nothing like seeing their book published in physical form. Nothing compares to holding a book in your hands and feeling the cover and touching the pages, especially if it is your own work written within.

While the fortunate few writers enjoy being published by the more mainstream publishing houses, many more turn to self-publishing as a means to get their book out for all to see and hopefully enjoy. Self-publishing means different things to different people. For some it may mean nothing more than vanity publishing, while to others it means hiring and paying a publisher that may specialise in self-publishing to take their manuscript and turn it into a real book. The author may also hire a publisher that will help them distribute their book and get it onto the bookshop shelves.

Publishing a physical book involves a lot of different operations, many or all of which the aspiring author may not feel qualified to handle. And that is ok, there are organisations that will take those frightening tasks away and handle all of them - for a price. Some writers, however, want to go it alone and handle everything themselves, becoming in effect their own publisher - that is self-publishing in a very literal sense.

One of the many publishing tasks that that last form of self-publisher needs to deal with is getting an ISBN - an International Standard Book Number - in order to make their book available to the widest possible audience through the book trade. The ISBN organisation is organised on a global scale to give every published work its own unique identifier. Since 2007 the ISBN has been a 13 character number. At that time the ISBN became part of the universal product numbering scheme known as the EAN, which numbers product from around the world. An ISBN consists of five parts or elements.

The first element is the prefix element, consisting of three characters which in the case of the ISBN are always either 978 or 979. The prefix element of the EAN signifies which country an article comes from. In the case of the ISBN, all books come from the fictitious land of Bookland, which is allocated the numbers 978 and 979.

The second element of an ISBN is the registration group element and shows the country, geographical area or language area of the book. It may be one to five characters in length.

The third element is the registrant element and shows the publisher of the book. The registrant element is up to seven character long.

The ISBN system is so arranged that larger countries with lots of publishers are designated shorter length registration group elements and longer length registrant elements in order to accommodate the larger numbers of publishers in bigger countries. Countries with smaller numbers of publishers, and needing fewer characters in the registrant element can be allocated a longer registration group element.

The fourth element in the ISBN is the publication element and signifies the actual publication or book. It can be up to six characters long. As with other elements, the available length depends upon the registration group element and the registrant element.

The final element, which always consists of one character, is the check digit. The function of the check digit is to help in confirming the validity of the other characters in the ISBN, to help with detecting transcription errors.