How Library Materials Are Shelved

Library materials uses the Library of Congress (LC) Classification Scheme to classify library materials. The Library of Congress in Washington D.C., from which the LC Classification System is derived, is the largest national library in the world. Though the LC Classification System is complex, users only need a general understanding of it in order to locate books on the shelves.

Call Numbers

Each item in the Library collections is assigned a Call Number which is a combination of letters and Arabic numerals. For example: LB 1049.M37 1983 c.2

  • Main Classes are represented by a single capital letter: e.g. L = Education.
  • Subclasses, with the exception of E and F, are designated by an additional capital letter: e.g. LB = Theory and Practice of Education.
  • Further divisions and subdivisions are designated by numbers ranging from 1 to 9999: e.g. LB1049. (These numbers may be extended using decimals.)
  • Author numbers follow, consisting of a single letter and Arabic numerals: e.g. M37.
  • Publication date is sometimes given: e.g. 1983.
  • Copy number is indicated where there is more than one copy in the Library: e.g. c.2.

How Books are Shelved

Books are shelved alphabetically by Main Class first. Within the Main Class, Subclasses follow. Hence, for example, the Subclass LB comes before the Subclass LC. After capital letters indicating Main Classes and Subclasses, books appear on the shelves by numerical subdivision number. After subdivision number, books are shelved by author letters and numbers. The filing is in a decimal system so that in the example below HD31.C3563 is shelved before HD31.C412.

When Call Numbers are exactly the same, books are shelved according to date of publication with the most recent one shelved last. 

HD             HD              HD             HD
31             31              31             31
.C3563         .C412           .C414          .C455
               1987            1989           1985
               c.2

Signs at the end of stacks indicate the range of Call Numbers which are shelved there. For example: K1 - K7624; BF - D; HD.

After finding a Call Number in the Catalogue, note the complete number and the location, e.g. "Circulation Collection", which refers to the Collection where the item is shelved.