Understanding Call Numbers 

Why do I need a call number? How do I find a book in the library?

Did you know that the call number — the number placed on the spine of the book — is a code, which provides valuable information about the book?

Each book in the library has a unique call number. A call number is like an address; it tells us where the book is located in the library.

Call numbers appear on the spines of books and in the online catalog (CUNY+).

What are call numbers for? 

Note that the same call number can be written from top to bottom, or left to right.

The Charles Evans Inniss Memorial Library uses Library of Congress Classification (LC) for call numbers. It is a combination of letters and numbers representing various subjects. LC is used in most academic libraries. School and public libraries use the Dewey Decimal Classification, with decimals and numbers.

What does the call number mean? 

The Library of Congress Classification arranges materials by subjects. The first sections of the call number represent the subject of the book. The letter-and-decimal section of the call number often represents the author's last name. And the last section of a call number is often the date of publication.

Why is this important to know?

Because books are classified by subject, you often find several helpful books on the same shelf, or nearby. For example, within the same call number LB2395, there are guides for college study.

Below is an outline of the Library of Congress Classification system:

A—General Works (General encyclopedias, reference books, etc.)
B—Philosophy—Psychology—Religion  
BF—Psychology
C—Auxiliary Sciences of History 
CB—History of Civilization
CC— Archeology
CS—Genealogy
CT—Biography General)
D—History (General and Old World)
D—World History
DA—Great Britain
DB—Australia
DC—France
DJ-DK—History of Eastern Europe
E-F—History of the Americas (Including the geography of individual countries)
E 1-143—America (General)
E 151-857—United States (General)
F 1-957—United States (States and local)
F1001-1140—Canada
F1201, etc.Other individual countries
G—Geography, Anthropology, Folklore, etc.
G—Geography (General)
GB— Physical Geography
GC— Oceanography
GN— Anthropology
GR— Folklore
GV— Recreation
H—Social Sciences
HA—Statistics
HB-HJ—Economics
HM-HX—Sociology
 J—Political Science
JA-JC—Political Science
JF-JQ—Constitutional history and public administration
K—Law
L—Education(General)
LA—History of Education
LB—Theory and practice of education
LC—Special aspects of education
LD—Individual  Institutions
M—Music
M—Scores
ML—Literature on music
MT—Musical instruction and study
N—Fine Arts
NA—Architecture
NB—Sculpture
NC—Graphic Arts
ND—Painting
NK—Decorative Arts
P—Language &Literature
P—Philology and linguistics
PA—Classical languages and literature
PC—Romance languages
PD-PF—Germanic languages, including PE—English
PG—Slavic languages and literature
PJ-Pl—Oriental languages and literature
PN—General and comparative literature
PQ—Romance literature
PR—English literature
PS—American literature
PT—Germanic literature
PZ—Fiction in English, Juvenile literature
Q—Science
QA—Mathematics
QB—Astronomy
QC—Physics
QE—Geology
QH—Natural History
QK—Botany
QL—Zoology
QM—Human anatomy
QP—physiology
QR—Bacteriology
R—Medicine
RA—Public aspects of medicine
RC—Internal medicine
RD—Surgery
RE—Ophthalmology
RJ—Pediatrics
RK—Dentistry
RL—Dermatology
RM—Pharmacology
RT—Nursing
S—Agriculture
SB—Plant culture and horticulture
SD—Forestry
SF—Animal culture
SH—Fish culture and fisheries
SK—Hunting sports
T—Technology
U-VMilitary and Naval Science
Z—Bibliography—Library Science
Letters I, 0, W, X, Y are not used yet.
Reading a Library of Congress Call Number
First Row — Letters 
The first row of letters in a basic Library of Congress call number represents a subject area. For instance, call numbers beginning with an “M” would be some type of music, and call numbers beginning with a “Q” would be some type of science, Items are shelved alphabetically by this first row of letters. The first row of the call number may consist of either one, two, or sometimes three letters. They would be shelved as in the following example:
AAB AG AZ BA BC
Second Row — Whole Numbers
The second row of a call number is made up of numbers. These numbers read as whole numbers and respresent a subdivision of the subject. They affect shelving in the following way:
A97 A104 A275 A350 A
1007 BlO
Third Row -- Decimal, Letter, Number
The third line in the basic LC call number is a decimal, letter, number “.H121”. The letter is usually the first letter of the author’s last name. However, for some subjects, for example in “P “, language and literature, this letter may be another subdivision to indicate the type of literature. Also, if the item has an editor rather than an author, the first letter of the title may be used. The number is called a “cutter number “. The numbers are read as a decimal. For example, this third line of the basic call number would be shelved in the following order:
A 97 .A27 A 97 .A277 A 97 .A3 A97 .B15
After the third line you may find another letter, number line on some items. This number is also read as a decimal. You may also find dates of items or volume numbers (V.1, V.2, etc.). You may find “P.1“ and ”P.2“ indicating parts, or ”C.1“ and “C.2“ indicating that the library has multiple copies.