Image by Enokson ©
At Kimberlin Library and the Law Library, we use the Dewey Decimal Classification system (DDC) to arrange books on similar subjects together. This classification system was invented in 1876 by Melvil Dewey. It is kept up to date and is widely used around the UK and the world in all types of libraries. Dewey organised all of the world’s knowledge into ten great divisions - hence decimal. These are called the main classes. Each subject comes under one of these classes and is assigned an appropriate class number. You may also see and hear this number called a shelfmark.
The ten main classes are: 
In order to identify all the elements that describe a book’s contents we expand the original number to give more specific
subject description:
So every book on the shelves at Kimberlin and the Law Library is assigned a class number, but to help locate the book you need even faster, the class number is always followed by letters, known as the filing suffix. This represents the first three letters of the author’s surname or the first three letters of the title if there is no author. This helps you to locate a specific book when there are many books on the same subject with the same class number. The books will be shelved in strict class number order and then alphabetically according to the filing suffix.