Erie Community College, State University of New York

How Books Are Arranged

Books in the Library Resource Centers (LRCs) are arranged on the shelves by call number, using a system called the Library of Congress (LC) Classification System.  You will find this system in use at most college and university libraries and at all branches of the Buffalo & Erie County Public Library.

It certainly is not necessary to know how this system was designed, or how books are given LC call numbers, to use the library.  But the more you know about the system, the better you will become at searching for and locating information.

Call numbers group materials according to subject matter.  A call number acts as a unique identification number for an item and allows you to locate the item on the shelf.

An LC call number is a combination of letters and numbers arranged in three or more lines.  Here is a quick breakdown of a typical call number:

• The first line consists of one, two, or (occasionally) three letters.  A single letter such as H comes before a double letter such as HA, and HM comes after HJ and before HX on the shelves.  The first letter of the call number is not usually the same as the first letter of the subject.  For instance, R represents Medicine, not Religion (which would be found in the Bs).  You can find a guide to subject areas and their corresponding letters further down in this document.
  
• The second line is a number ranging from 1 to 9999.  The numbers within each alphabetical section (HA or HM or HJ) progress in normal numerical order on the shelf.
  

• The third line of the call number will start with a decimal point, then a letter followed by one or more numbers.  Items are shelved, first, alphabetically by the letter, e.g., .A, .C, .M.  The decimal point is observed, so, for example, .B27 will be shelved before .B4.
  

• A fourth or subsequent line is usually used to indicate the year the item was published.  

Remember, look line by line at the call numbers—each line is a subdivision of the preceding line.  And no two items in a library will ever be assigned the same call number.

Here are two examples of call numbers in action:

Author:              Silberman, Matthew

Title:                 A World of Violence: Corrections in America

Call number:    HV             (Social pathology)

                         9025          (Prison violence)

                         .S55            (Author: Silberman)

                         1995           (Published in 1995)

Author:              Small, Meredith F.

Title:                 Our Babies, Ourselves

Call number:    RJ               (Pediatrics)

                         61               (Popular works)

                         .S6345        (Author: Small)

                         1998           (Published in 1998)

Don’t be surprised if you sometimes see the call number written horizontally.  For example, the above call numbers might appear as:

 HV9025.S55 1995 and RJ61.S6345 1998

 
Here is a list of the major Library of Congress subject areas:

A            General works

B            Philosophy, psychology, religion

C            Auxiliary sciences of history

D            History: general and Old World

E-F         History: western hemisphere

G            Geography, anthropology, recreation

H            Social sciences

J             Political science

K            Law

L            Education

M            Music

N            Fine arts

P            Language and literature

Q           Science

R           Medicine

S            Agriculture

T            Technology

U            Military science

V            Naval science

Z            Bibliography, library science

Library of Congress Classification Outline -  Lists the letters and titles of the main classes of the Library of Congress Classification.