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How to read a call number

NSCC Campus libraries organizes the books, videos, etc on the shelves using the Library of Congress Classification System (LCCS). This system is a system of letters and numbers (called call numbers) used to arrange materials so items on the same topic are usually shelved together.

Parts of a Call Number

Here's the call number for The art & science of Java: an introduction to computer science by Eric S. Roberts.

Illustration of of a call number.

The first couple of lines are the book's subject. QA 76.73 is on computer software. J73 is for Java. This puts all the books on computer software in the same place and the books on Java usually in the same area within them.

The next line a code for author's last name. In this case R63 stands for Roberts. So all the books by Eric Roberts on the Java should be in the same place on the library shelves.

The last line, 2008, is the date of publication.

Tips for Finding Books on the Shelf

When you are checking the shelves for a book, read call numbers line by line. Consider the call number
QA 76.73 J38 R63 2008.

QA Look on the shelves for the Q section, QA is within that section.
76.73 Now look for the second line within the QA section. Read it as a number, e.g. 1, 2... 75, 76, 76.73...Read the numbers after the decimals one digit at a time, e.g. QA 76.73 reads as "Seventy-six point seven point three" and not "Seventy-six point seventy-three." So QA 76.73 comes before QA 76.8!
J38 Now find the next line within the QA 76.73 range. Read the letter alphabetically and the number as a decimal extension, that is, one digit at a time, e.g. J point 2... J point 37... J point 38.
R63 Treat this line the same way as the previous one. By now you should be very close to the book.
2008 The last line is usually a date, so read in chronological order: 2005, 2006... 2008!

Here is a shelf of books with the call number order explained.

Illustration of a shelf of call numbers.

For more help

Contact the library for more help.

Updated January 21, 2014