Skip to main content

Engl110-Lovitt: Finding Books

Search DELCAT Discovery

Search Libraries worldwide, including DELCAT, for books, articles, DVDs and more

Advanced Search

Finding Books in the Library

Libraries arrange items according to a classification system.  You may already be familiar with the Dewey Decimal System, which is used in most public and high school libraries.   The UD Library uses the Library of Congress Classification System.  Each book (or bound volume of a journal) is assigned a call number – a unique number that specifically identifies one copy of one book. 

A book is shelved according to its call number.  Therefore, the call number also serves as a book’s address in the building.  Like the Dewey Decimal System, the Library of Congress Classification System groups books on the same subject together on the shelves. 

The first letter of the call number indicates the floor on which that call number is shelved.  The different call numbers are on different levels in the library:

A - H 3rd Floor
J - K Lower Level
L - N 3rd Floor
P - Q 2nd Floor
R - Z Lower Level


Using DELCAT Discovery

Understanding Call Numbers

A call number is always read line-by-line, from top to bottom.  Library of Congress call numbers always start with letters – typically one or two letters, sometimes three. Example: D 25 .A2 1994

The first line reads alphabetically:

D                DA              DB               DC    

The second line is a whole number and is read numerically, like this:

D 25               D 26         ...          D400          ...         D1200

The third line begins with a decimal point.  It is a combination of a letter and a number.  The letters are read alphabetically, but the numbers are read as decimals, not as whole numbers. 

D 25 .A2           D 25 .A24                   D 25 .A3               D 25 .A5             D 25 .A55

Here is an example of complete call numbers, as you might see them in order on the spines of books on the library shelves:

R

733

.H376

2004

R

733

.N38

2004

R

733

.N87

2003

R

733

.P755

2007

Different Collections

Special locations might be listed before the call number, if the book is part of a specific collection, such as those housed within the branch libraries (outside of the main library) or specific collections within the main library.

Examples of special locations:

Special Collections 2nd Floor, closed stacks
Library Annex Off-campus; you can request items from the Annex using a form.
Reference 1st Floor, in the Reference room

Ask the Library

Close This