A call number is like an address--it tells you where in the library you can find an item.

Here is an example of a call number for a book from our library. Let's see what a call number is made up of:


TK--The first letter or letters represent the General Subject Area--in this case, 'TK' stands for Electrical Engineering; Electronics; Nuclear Engineering

5105.882--the numbers in the second line of the call number represent a more specific subject area--here, it stands for aspects of, or services on the internet, browsers.

.M39-- Author or title. For this book, it stands for Maze, Susan.

1997-- Year of publication.

This book is Authoritative Guide to Web Search Engines by Susan Maze.

Here's another one:

E--The General Subject Area is United States History

332--This more specific subject area represents biographies of Thomas Jefferson.

.R196--This stands for the Author's last name, in this case Randall.

1993--Year of publication.

The book is Thomas Jefferson: a life by Willard Sterne Randall.


Call numbers are read line by line.

1. Read the first line in alphabetical order:
A, B, BF, C, D, ...L, LB, LC, M, ML ...

2. Read the second line as a whole number:
1, 2, 3, 45, 100, 1000, 2000, 2340 ...

3. The third line is a combination of a letter and one or more numbers. Read the letter alphabetically. Read the number(s) as a decimal.
.C65 = .65 .C724 = .724

Example: .B before .C -or- .34 before .55 -or- .554 before .63

Some call numbers have more than one combination letter-number line.

Example: RC 607 .A26 S56 1989
RC stands for internal medicine
607 .A26 stands for AIDS
S56 represents the author's last name--Silverstein
1989--the year of publication.

The book is AIDS: deadly threat by Alvin Silverstein.

4. Read the date chronologically:
1776, 1848, 1929, 1964, 1998, 2003

Some call numbers don't have dates, especially if it represents the first edition of a work or if it was published before 1982 (that's when the Library of Congress began requiring that the date be added to the last line of all call numbers).


Here are some sample "books." Look at how they are placed in call number order.