Understanding Call Numbers

Library of Congress Call Numbers

The LC Classification System is also subject based, classifying and arranging items by the subject matter involved. LSU Libraries uses LC call numbers for most of it's books.

  • The LC system is broken into 21 primary classes, or general subject areas, represented by letters.

  • By breaking items into 21 subject areas rather than the 10 of Dewey, the LC classification system allows libraries to classify and arrange larger collections.
    • A - General Works
    • B - Philosophy. Psychology. Religion
    • C - Auxiliary sciences of history
    • D - History
    • E,F - History in Americas
    • G - Geography
    • H - Social Sciences
    • J - General legislative and executive papers
    • K - Law
    • L - Education
    • M - Music and Books on Music
    • N - Fine Arts
    • P - Language and Literature
    • Q - Science
    • R - Medicine
    • S - Agriculture
    • T - Technology
    • U - Military Science
    • V - Naval Science
    • Z - Bibliography. Library Science

  • The LC system further breaks these subjects into subclasses by the addition of one or two letters followed by numbers up to four digits plus several decimal places in length. For example:
    • LC call numbers beginning with Q Science
    • LC call numbers beginning with QL deal with Zoology
    • LC call numbers beginning with QL 700 deal with mammals
    • LC call numbers beginning with QL737 deal with Gorilla Behavior
      The LC call number for Gorillas in the mist , by Dian Fossey is:
      QL737 .P96 F67 1983

  • For a list of the major classes and subclasses of the LC classification system, click HERE.

  • The second part of an LC call number includes a code representing the author and the particular item. This part of the call number begins with a letter followed by numbers, and them sometimes another letter followed by numbers.
    For example, Gorillas in the Mist:
    QL737 .P96 F67 1983

  • Frequently an LC call number will include a final part which represents the year that the item, or particular issue of an item, was published.
    Again, Gorillas in the Mist:
    QL737 .P96 F67 1983


< < PREV