Have you ever wondered how books and journals in Saint Louis University Libraries are assigned their places on the shelves? The call number, the number placed on the spine of the book, is a code that provides valuable information about the book. The SLU Libraries Catalog will help you find the call number for each item you want.

What are call numbers?
Each book in the library has a unique call number. A call number is like an address in that it tells you where the book is located in the library.

Call numbers appear...

Reading call numbers:
SLU Libraries, like many academic libraries in the United States, uses the Library of Congress classification system for call numbers. This system uses a combination of letters and numbers to arrange materials by subject.

What does the call number mean?
The Library of Congress Classification System arranges materials by subject. The first sections of the call number represent the subject of the book. The letter and decimal section of the call number represent the author's last name. The last section is the year the book was published, but not all books will have this included in the call number.

Putting call numbers in shelf order:
This diagram should help you understand how to find your book on the shelf after you have gotten the call number. For locating materials, please consult the Location Guide for Pius Library.

Last updated May 3, 2007.