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Understanding Library of Congress Call Numbers: Understanding Library of Congress Call Numbers

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Understanding Library of Congress Call Numbers

Library of Congress call numbers are arranged alphabetically and numerically. Read call numbers from left to right and from top to bottom.

 

Letters in the first line of the call number are alphabetical:

H45
.E37
1984
HA155
.A5
1944
HB21
.A33
1982
HC13
.S47
1990

 

Numbers in the first line of the call number are in numerical order:

B53
.D476
1990
B785
.L44
M67
1991
B1201
.B44
W64
1997
B1246
.R66
1986

 

Letters in the second line are alphabetical:

KF240
.B265
1981
KF240
.C538
1989
KF240
.S795
1995
KF240
.T38
1989

 

Numbers in the second line of the call number are in decimal order. It is important to remember that there is an “invisible” decimal point between the letter and the number:

L901
.C33
L901
.C34
1971
L901
.C343
1976
L901
.C37
1996

 

There may be a third line of letters and numbers. These will also be in alphabetical and decimal number order.

The last line of a call number may be a year. This indicates the publication date.

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