Call Numbers

Library materials are arranged by a combination of letters and numbers. This combination is called a “call number” (e.g.: LC3981 .G5 2007). The library uses the Library of Congress (LC) Classification System for most of the collection. Medical and pre-clinical subjects are classified under the National Library of Medicine (NLM) Classification System.

Reading a Library of Congress call number

In this example, the book is Effective Instructional Strategies: from Theory to Practice, by Kenneth D. Moore. It is published in 2009. 

The first two lines describe the subject of the book.  

LB = Theory and practice of education; LB1025.3 = Teaching principles and practice

The third line typically represents the author, editor, or title of the book; in this case, M662 = Moore

The fourth line represents the date of publication, 2009

Here are the classes, or basic subject categories of the LC classification system:

Note: Our medical and pre-clinical subjects are classified under the National Library of Medicine (NLM) classification system. While there are no Ws used in the Library of Congress system, NLM uses the entire W range in its call numbers. This allows the NLM system to co-exist with the larger LC coding scheme as neither of these ranges are used in the LC system. NLM also uses a range of starting letters from QL, QS-QZ.

National Library of Medicine call numbers

Here are the classes of the NLM classification system: