Call Numbers (Library of Congress Classification): Call Number Basics

Reading Library of Congress call numbers and a browsable outline of the Library of Congress Classification scheme.

Library Call Numbers - A Quick Look

College and university libraries arrange books and other items on their shelves using Library of Congress call numbers - public and school libraries use Dewey Decimal call numbers.

Each item in the library has its own unique call address that tells you where the books is located in the library.

Call numbers can be found on the spines of books and in the online catalog - they can be written from top-to-bottom, or left-to-right!

Library Call Numbers - A Closer Look

Call numbers are very important in libraries...they tell you the exact address or where the book is found in the Library.

Most college and university libraries, including the HCC Library, use Library of Congress call numbers to organize their materials. Most public and school libraries use Dewey Decimal System call numbers.

A call number will start with 1-3 letters. The following is a chart of what the first letter in a call number stands for, according to the Library of Congress scheme:

A General Works
B Philosophy, Psychology, Religion
C Auxillary Sciences of History
D History: General & Outside the Americas
E History: America & United States
F History: United States Local & America
G Geography, Anthropology, Recreation
H Social Sciences
J Political Science
K Law
L Education
M Music
N Fine Arts
P Language, Literature
Q Science
R Medicine
S Agriculture
T Technology
U Military Science
V Naval Science
Z Library Science & Information Resources

The second (or sometimes there's even a third) letter in a call number narrows down the subject even more. For example, a book with a PR call number is about English literature, and a book with a PS call number is about American Literature.

The second line of the call number will contain numbers. Depending on the book a call number may contain several lines, for example:


Just remember, when reading a call number to follow letters, then numbers.