A call number is like an address: it tells us where the book is located in the library. Call numbers appear on the spines of books and in the library catalog. Note that the same call number can be written from top to bottom on the spine label or left to right in the catalog.

How do you read call numbers?

Look at each section of the call number in the illustration below.


How are call numbers put in order on the shelf?

To understand how call numbers are put in order using the Library of Congress Classification system, again look at each section of the call number.


What does the call number mean?

Like many academic libraries in the U.S., the MSJC Libraries use Library of Congress Classification for call numbers. This system uses a combination of letters and numbers to arrange materials by subjects. Each book in the library has a unique call number representing its main subject, and usually the author or editor, and/or the title. The first sections of the call number represent the subject of the book. The letter-and-decimal section of the call number often represents the author's last name or the title. And the last section of a call number is usually the date of publication.

Why is this important to know?

Because books are classified by subject, you can often find several helpful books on the same shelf, or nearby. For example, within the same call number LB2395, there are other guides for college study.
Since Library of Congress Classification arranges materials by subjects, knowing the letter(s) for your subject area gives you a place to start browsing the shelves. Which letters represent your subject? Click here to look at the subject letters on the Library of Congress Classification Table.