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Call Numbers: What Is a Call Number?

What call numbers are and how to use them

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 Brighton: (585) 292-2303
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Created by Stephanie Hranjec, based upon a print-based brochure by Alice Wilson.

All graphics for this guide provided with permission from Honolulu Community College Library.

What Is a Call Number?

A call number is like a house address. It tells you where you can find an item in a library. Each item owned by a library has its own unique call number. 

Call numbers appear:

Reading Call Numbers

Call numbers are usually on the spine of a library item, so they can be easily read on book shelves. Sometimes, when a spine is too narrow, the call number will be on the book's cover.

In our online library catalog, call numbers are displayed on the results page in the column titled Call Number. You can also find a book's call number by clicking on Is it here?

Library of Congress Classification System

MCC Libraries arranges its material according to the Library of Congress Classification System. This system files books and other resources by subject. Call numbers start with a letter or letters that represent the broad subject area under which the book falls. 

For example:

  • L=Education
  • LB=Theory and Practice of Education
  • N=Art
  • NK=Sculpture, Modern
  • R=Medicine
  • RT=Nursing