Skip to Main Content
Library and Tutoring homepage

Information Literacy Modules: Identifying Types of Information Formats in Relation to Access

Moving Forward

Primary sources

1 of 7

2 of 7

3 of 7

4 of 7

5 of 7

6 of 7

7 of 7

Library of Congress Classification System

1 0f 6

2 0f 6

3 0f 6

4 of 6

5 of 6

6 0f 6

Call Numbers or how is the library organized?

Call Numbers

After you find an item in the catalog, you will need to locate that item on the shelf. Every item in the library is labeled with an alpha numerical designation or call number. The catalog record will display the individual call number for each item.

Think of a call number as an item's address on the shelf. The SJR State Libraries use a call number system devised by the Library of Congress. Library of Congress (LC) call numbers keep materials about the same subject together on the shelf by dividing subjects into different classes.

Each class is identified by a letter. Classes may then be divided into more specific sub-classes by adding more letters. Sub-classes can be made even more specific by adding numbers. The first line in an LC call number classifies that item by its subject classification (those subject headings that we discussed earlier).

For example, a book written in 1990 by Cheryl Simon Silver entitled One Earth, One Future has the call number GF 75 .S55 1990

  • GF represents geography, specifically human ecology
  • 75 indicates it focuses on global warming
  • .S55 is based on the author's last name
  • 1990 represents the year of publication

Call Numbers


To find an item on the shelf, write down the call number and follow the steps in the guide below to locate the item labeled with that call number.