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How to Read Call Numbers

How to Read an LC Call Number

Line 1: Alphabetical order - A, B, C, D, DA, DB, DB, etc.
Line 2: Numerical order - 1,2, 3, 4, 1000, 2000, 3000, etc.
Line 3: Letters in alpha order, numbers in decimal order-
ex. .A2 goes before .A23 but after .A12
Line 4: Chronological order - 1992, 1995, 1999, 2001, etc.

What Does it Mean?

Books on the shelves are arranged by the Library of Congress Classification System - a system used by most academic libraries. Every combination of numbers and letters defines a subject. For example - if you browse the N section, every book with this call number is about Art.

• The first line of a call number contains 1, 2, or 3 letters, which broadly define the subject area. For example: K - law in general, KF - law of the United States.
• The second line of the call number is a number, which further defines the subject. For example: books with the call number QE534.2 (Q is science) are about "Earthquakes, Seismology - General Works - 1970 to Present."

LC Classification Chart