How do I read a call number on a book?

The Kathryn A. Martin Library uses the Library of Congress Classification System to organize our collections. The books are found on the third floor (A-L) and fourth floor (M-Z).

Let's look at an example. Take the book Colorblind Injustice: minority voting rights and the undoing of the Second Reconstruction, by J. Morgan Kousser. 


The call number will look like this in the Library Catalog:  JK1924 .K68 1999

But it will look like this on the spine of the book:

JK 1924 .K68 1999

You read the call number from the top down.

  • The "JK" or beginning letters (anywhere from 1 to 3 letters) represent the subject area of the material. Books are arranged alphabetically by these letters on the shelf.
    This book will be on the third floor of the library in the J section.
  • The "1924" or next digits can be read all together. 1924 will be after 1900 and before 2000. 
  • The ".K68" or decimal-letter-number combination is read character by character. First find the 1924.K books. Then move to the right until you find the 1924.K6 books. Continue moving right until you find the 1924.K68 books. (At this point you might be able to spot the title of the book you're looking for on the shelf.)
  • The last number is the year of publication.

 Check with a librarian if you need assistance.


  • Last Updated Jul 25, 2022
  • Views 45
  • Answered By Kate Conerton

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