A call number is a unique alphanumeric classification or "address" used to arrange books and other items on library shelves. Most of the library's General Stacks collection is organized by the Library of Congress classification system, which groups items by subject (example: PR6015 .A33 W57 2001).
Children's and juvenile materials are organized primarily by Dewey Decimal classification (example: 398.2452 Pin 2009).