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:

A General works
B Philosophy, psychology, religion
C Auxiliary sciences of history
D World history 
E-F History of the Americas 
G Geography, anthropology, recreation
H Social sciences
J Political science 
K Law
L Education
M Music
N Fine arts
P Language and literature
Q Science
S Agriculture
T Technology
U Military science
V Naval science
Z Library and information science

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:

QS Human anatomy
QT Physiology
QU Biochemistry, cell biology, genetics
QV Pharmacology
QW Microbiology and immunology
QX Parasitology
QY Clinical pathology
QZ Pathology
W General medicine. Health professions
WA Public health
WB Practice of medicine
WC Communicable diseases
WD Disorders of systemic, metabolic or environmental origin, etc.
WE Muscoloskeletal system
WF Respiratory system
WG Cardiovascular system
WH Hemic and lymphatic system
WI Digestive system
WJ Urogenital system
WK Endocrine system
WL Nervous system
WM Psychiatry
WN Radiology. Diagnostic imaging
WO Surgery
WP Gynecology
WO Obstetrics
WR Dermatology
WS Pediatrics
WT Geriatrics. Chronic disease
WU Dentistry. Oral surgery
WV Otolaryngology
WW Opthalmology
WX Hospitals and other health facilities
WY Nursing
WZ History of medicine. Medical miscellany