Call numbers are assigned to each book/journal in order to:

  • Give you a way to locate the book/journal on the shelf by looking for its unique number
  • Arrange books/journals on the shelf in broad subject categories; books with the same call number are on the same subject, so you can find them together

What is a call number?

The call number for a book/journal is the combination of letters and numbers that appears in the online catalog record for the book/journal and on the spine of the book/journal. The University libraries use the library of Congress classification system of call numbers. This system uses one or two letters to indicate the subject area of the book/journal. Successive numbers and letters are used to represent a further definition of the specific subject covered by the book/journal and also to represent the author's name.

LA    L    = Education; LA = History of Education
229    229    = Student life within the history of higher education in the United States
L28    L    = First letter of author's name
  28    = "cutter number" to represent author's name. "L28" is assigned so this book will shelve alphabetically by author with other books on the same subject. There is an invisible decimal point in the "Cutter number" which causes it to be read L.28 or L2.8. The first numbers are the whole numbers.

How to Locate Library Materials by Call Number

First: Note the specific library location


Dewey, EXT Dewey Graduate Library Downtown Campus
SCI Science Library Uptown Campus, between the Campus Center and SEFCU Arena
ULIB University Library Uptown Campus, Podium

Second: Note where it is in the University Library

A thru L Third Floor
M thru Z Second Floor
*,**,***, OVER Second Floor, NE
GovDoc Basement
Innovate, Make, Create Center (IMC) Basement
Juv, juvenile Basement Floor (behind IMC)
Law First Floor, SW
Mic Basement
over* Second Floor, NE
PER Basement
RBR Circulation
Ready Ref - at the beginning of Reference First Floor, SW
Ref First Floor, SW

How are Call Numbers Arranged?

Basically, call numbers are arranged alphabetically and numerically by the letters and numbers that comprise the call number.

  1. The first line of a call number is almost always a letter or two letters (occasionally 3 - ex. KFN). A single letter will shelve before the same letter followed by another letter :


    P before PE, L before LA


  2. The second line of the call number is a whole number. It may be extended with a decimal :


    10 before 100, 35.2 before 350, 759 before 7337.


  3. The third line of the call number is treated as a decimal, although it does not contain a decimal point. Any line subsequent to the first that begins with a letter is treated as a decimal number

  4. In cases where a book has been republished in a new or revised edition, the new date of publication is added at the end of the call number to distinguish it from other editions of the same book.

If the Book You Want is Not on the Shelf

  1. First, check the call number to see if the book is already checked out to someone else, is on Reserve, or has some other special status.

  2. If not, ask at the Circulation Desk to have a search done on the book.

Still Have Questions?

Librarians are standing by 24/7, ready with answers. Go ahead, ask us!