How to read a call number

Call numbers serve two functions:

  1. They provide a unique “address” for every item within the library.
  2. They group items by subject so that it is possible to browse the shelves around it to find other items nearby on the same or similar subject.

What do these call numbers mean?

Let’s start with the call number in the example below: HQ1233 .B25 1992

Library Leddy Library
Title Enterprising women : television fandom and the creation of popular myth
Author Bacon-Smith, Camille
Publication Date c1992
Publisher University of Pennsylvania Press
Call Number HQ1233.B25 1992
Available Leddy: Book Collection (circulating) - Main Bldng

HQ - The first letter represents one of 21 major subdivisions of the Library of Congress Classification System (LC). The second letter represents a subdivision of the major subdivision. In this example, the letter “H” represents social sciences. The letter “Q’ represents “The family. Marriage. Women.” which is a subdivision of the social sciences.

1233 - The first set of numbers in a call number help to define a book’s subject. In this example, the number “1233” represents “Women and Feminism.”

.B25 - The letter/number combination after the first period usually represents the author, or in some cases the title; this allows for items on the same topic to be shelved alphabetically.

1992 - The year of publication often appears at the end of the call number.

How would I find it on the shelf?

Using the above example
  • The first step is to find the HQ section which be located after the HN's but before the HV's. 
  • Use this chart of call number locations to determine where the HQ section is in the Leddy Library
  • The next step is to find 1233 which would be located after 1229 but before the 1236. 
  • The last step is to find .B25 1992 which would be located after .B2 2001 but before .B6 1895.
Tips for understanding call numbers
  • The first part of a call number begins with one, two or three capital letters which are filed alphabetically.
  • The second part is a number which are filed numerically.
  • The third (and sometimes fourth) part is a letter followed by numbers. The letter is read alphabetically and the numbers is always read as a decimal.
  • Often the last part is the year the material was published.
  • Read the call numbers from left to right.
  • Often call numbers can be quite long. Do not be intimidated or overwhelmed! The best thing to do is to break the call number into smaller parts.
  • If you can't find what you are looking for, please visit the Circulation Desk or the Reference Help Desk - we don't want you to leave empty-handed!