Classmark

A classmark, also known as a shelfmark, is a series of numbers and letters which are printed on the spine of a library book. These are used to help you find the location of the book in the library. We use the Dewey Decimal Classification system to classmark items.

The Dewey Decimal Classification (DDC) is the system we use to organise everything in the library. It sorts all knowledge into ten main subject areas, each represented by a number between 000 and 999. This helps you find exactly what you’re looking for, whether you’re after a textbook, a research source, or just something interesting to read.

Here’s a quick overview of the ten main Dewey categories:

  • 000–099: General works — encyclopaedias, trivia, and other reference materials

  • 100–199: Philosophy and psychology — theories of thought, mental health, and related topics

  • 200–299: Religion — beliefs, practices, and world faiths

  • 300–399: Social sciences — politics, law, education, economics, and more

  • 400–499: Language — from English grammar to foreign languages

  • 500–599: Science and mathematics — biology, chemistry, physics, and natural sciences

  • 600–699: Technology — medicine, engineering, business, and practical skills

  • 700–799: The arts — visual arts, music, design, and performance

  • 800–899: Literature — novels, poetry, drama, and literary analysis

  • 900–999: History and geography — historical events, travel, biographies, and maps

 

Each of these areas is divided into even more specific topics, making it easier to locate resources on exactly what you need.

Here is an example of the classmark of a book about the DDC classification: 025.431 Sat The letters are the first three letters of the author's surname. 

If you’re unsure where to start, ask a member of the library team — we’re here to help you navigate it all.