Structure and Format
of Call Numbers
LCCS Training Sessions
OSU
July 2007
Definitions
Call number – an alphanumeric
designation that uniquely identifies a
bibliographic item.
 The call number is printed on a label
affixed to a bibliographic item so that the
item can be shelved and found.

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Class Numbers and Book Numbers
Consists of class number (also called
classification number) and a book
number (also called a Cutter number)
 Class number  subject of the work
 Book number organizes works within a
class
 May also include other information
(notably a date)

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System Structure

21 classes using
letters
A
General works
B
Philosophy. Religion
C
History: Aux. sciences
D
World history and history
of Europe, Asia, Africa, etc.
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
R
Medicine
S
Agriculture
T
Technology
U
Military science
V
Naval science
Z
Bibliography. Library
science. Info resources
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System Structure (cont.)

Subclasses usually designated by a
second letter (exceptionally by a third in D
and K)
Q
Science (general)
QA
Mathematics
QB
Astronomy
QC
Physics
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Notational structure
Alphabetic subclasses are further divided
by sequential cardinal numbers from 1 to
9999
Example:
QC 1-75
Physics in general
QC 81-114
Weights and measures
QC 120-168.85 Descriptive and
experimental mechanics

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Notational Structure (cont.)
Note that classes use whole numbers and
are arranged in numerical order, e.g.,
QH1
Natural history - Periodicals
QH44
Works about Linnaeus
QH135
Natural history –
Biogeography – Europe – General works

QH705
Economic biology
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Notational structure (cont.)

Decimal numbers are sometimes used
when topics are added
Example:
QC 814
QC 815
QC 815.2
Early works through 1800
General works, treatises, & textbooks
1801-1969
1970-
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Cutter Numbers in Classification
In LCCS, Cutter numbers are sometimes
used to subdivide classes
 Most common: Geographic Cutters

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Cutter Numbers in Classification
(cont.)
Example:
Geomagnetism QC 811-QC 849
Observatories
QC 818.A2
General works
QC 818.A5-Z By region or country, A-Z
A work on geomagnetism observatories in
Canada would be classed in QC818.C2
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Cutter Numbers in Classification
(cont.)
This results in two Cutter numbers:
Subclass division
2. Cutter for main entry
1.
Example:
The geomagnetism observatories of Canada /
by I.M. Lodestone.
QC818.C2 L64 2005
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Cutter Numbers in Classification
(cont.)
Except in Class G, no more than two
Cutter numbers are allowed
 In some cases, two Cutter numbers are
used in the classification schedules.

1st Cutter is for a topical subclass
 The 2nd Cutter is for a geographic country or
locality or name of a corporate body, etc.
 A digit is added to the second Cutter for the
main entry
 The
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Cutter Numbers in Classification
(cont.)
Example:
Propaganda and censorship during Canada’s
great war / by Jeff Keshen, 1996.
D639 class number for World War I
.P7
subclass for propaganda
C24
sub-subclass for Canada; added digit
for Keshen
1996
year of publication
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System Structure
7 categories provide structure within each
schedule as well as within subcategories
•
•
•
•
•
•
•
Physical format
Philosophy
Study and teaching
General works
Laws and regulations
Juvenile works
Topical subdivisions
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