Understanding Classmarks

The classmark tells you the order in which books and journals are shelved within a collection. It is determined by the classification scheme which organises books and journals into subjects. Although classification schemes can get very detailed and complex, it will help you to find a book or a journal on the shelf if you have a broad understanding of how the different schemes work.

The Library uses three main classification schemes:

Bliss Classification - an alphabetical code used to group books by subject, e.g. MUDV

  • Books are shelved alphabetically according to the code, hence MT is shelved before MU which is shelved before MUDV.
  • Within each subject books are shelved alphabetically according to the author or first word of the title, hence MUDV/Abr is shelved before MUDV/Wil.

Dewey Classification - a numerical code used to group books by subject, e.g. 016.78

  • Books are shelved numerically according to the code, hence 016 is shelved before 016.7 which is shelved before 016.78.
  • Within each subject books are shelved alphabetically according to the author or first word of the title, hence 016.78 [Abraham] is shelved before 016.78 [Williams].

Library of Congress Classification - an alphabetical and numerical code used to group books by subject, e.g. LE36.S32

  • Books are shelved alphabetically according to a subject code, hence L is shelved before LE. Read the number as a whole number: 1, 36, 2730.
  • Any following lines are a combination of a letter and numbers. Read the letter alphabetically, and read the number as a decimal, eg: .S32 = .32 A last line sometimes used is the year the book was published, read in chronological order.

Old Classification - an alphabetical code used to group books and journals by subject, e.g. AB

  • Books and journals are shelved alphabetically according to the code, hence AB is shelved before C which is shelved before I.
  • Within each subject books and journals are shelved alphabetically according to the author or first word of the title, hence AB [Essays] is shelved before AB [Journal].

Remember that in order to find a book or journal in the Library you also need to know the location code which prefixes the classmark.