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Locating Books: Locating Books

This guide will explain how to use the Library Catalog to search for various types of material available from the Library searching by keyword, subject, author, etc.

What is a call number?

Call numbers are a code to identify each unique book by its subject matter. Because books are arranged by the call number, it also acts as a shelf address. You will find the call number attached to or written on the spine of each book. The Alkek Library uses Library of Congress call numbers that uses letters and numbers to arrange books by subject. Books on similar subjects are assigned similar letters, based on the Library of Congress call number system.

A: General Works

H: Social Sciences Q: Science 

B: Philosophy. Psychology. Religion.

J: Political Science R: Medicine 

C: Auxiliary Sciences of History

K: Law  S: Agriculture 

D: History: General & Old World

L: Education  T: Technology

E: History: America

M: Music and Books on Music    U: Military Science

F: History: America

N: Fine Arts  V: Naval Science

G: Geography. Anthropology. Recreation   

P: Language and Literature  Z: History of Books. Library Science. Bibliography.

Locating Books by Library of Congress Call Number

Library Catalog record explained: 

  • Location, Floor Consult a call number map to find them.
  • Call Number (the book's address on the shelf)
  • Status (whether the book is Available or if someone else has it checked out)


Reading a call number

Books are arranged on the shelves by their Library of Congress call numbers. You can think of this number as an address for the book. Break it down and read it one line at a time as follows:


Line 1: Call numbers are arranged first in alphabetical order. All books with call numbers that start with LC will be between L and LD.

Line 2: Within the LC call numbers, books are arranged in number orderLC 5131 will be between LC 5000 and LC 5150 

Line 3The last part of the call number consists of a letter and a number. The letters are read in alphabetical order. Read the numbers as decimal numbers, not whole numbers, so .T75 is read as T.75 -- LC 5131 .T75 is between LC 5131 .T70 and LC 5131 .T8