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Call Numbers

Learn how books are organized and labeled at Northwestern University Library

Superintendent of Documents (SuDoc) Numbers

SuDoc numbers are assigned by the Government Printing Office to materials published by federal agencies and distributed to Federal Depository Libraries in paper, microfiche, and CD/DVD formats.  NUL has been a depository library for more than 100 years and receives approximately 75% of the materials made available to depository libraries.

SuDoc numbers organize materials by the publishing agency, not by subject as in Dewey or LC.  Usually, but not always, the name of the agency provides the first letter(s) of the SuDoc call number.  

A few examples (to see a complete, current list):

A    Agriculture
C    Commerce
D    Defense
E    Energy
 ED    Education
 EP    Environmental Protection Agency
J    Justice
L    Labor
S    State
Y    Congress

 

There is a variety of punctuation used in SuDoc numbers.  You will see periods (.) colons (:) slashes (/) and dashes (-). However all numbers that you see are whole numbers, not decimals, and should be filed in whole number order, wherever they appear in the call number.

 

SuDoc Shelving Order

SuDoc numbers are made up of the STEM (all the letters/numbers/punctuation BEFORE the colon) and the SUFFIX (everything that FOLLOWS the colon).

SuDoc classes are arranged alphabetically based on the leading letter(s) in the stem.  SuDoc classes file alphabetically no matter how many letters are used (ex. L comes before LC;  N comes before NAS which comes before NS). 

The number in the stem between the period and colon is a whole number (ex. HS 1.2: comes before HS 1.15:).

Both before and after the colon, an empty space will file before a space that has a letter or number (i.e. “nothing” before “something”).

FILING RULES SAMPLE SUDOC SEQUENCE

   :  before /

 Y4.Sci2:
 Y4.Sci2/2

  T22.19:M54

  T22.19:M54/990

  T22.19/2:P94

  T22.19/2:P94/2

  T22.19/2:V88/retest

  T22.19/2:V88/retest/989

  T22.19/2:V88/test/989

  T22.19/2:V88/test-2/988

  T22.19/2:V88/test-2/989

  T22.19/2:V88/989/student/militia

  T22.19/2:V88/989/student/spanish

  T22.19/2:V88/989/student/text

  T22.19/2:V88/990/student/spanish

  T22.19/2:V88/2

  T22.19/2:V88/2/989

 

 

 

 

 

   - before /

 Y4.Sm1:
 Y4.Sm1-10:
 Y4.Sm1/2:

    letter before date

 I 29.2:G76/4/cult.
 I 29.2:G76/4/987

 L37.2:Oc1/2/conversion
 L37.s:Oc1/2/991

    date before number

 J29.2:D84/982
 J29.2:D84/2

 L36.202:F15/990
 L36.202:F15/991
 L36.202:F15/2

    letter before number

 Y3.El2/3:B21/2
 Y3.El2/3:1/

 Y3.M58/summ.
 Y3.M58/2

 Y4.Ed8/1:101-Q
 Y4.Ed8/1:101-1

 Y4.N95:N95/pts.1-15
 Y4.N95:N95/5/pt.3

    nothing before something

 GS1.2:So2
 GS1.2:So2/4

 L2.3;16:
 L2.3/16-2:

 Y4.F76/1:C42/4
 Y4.F76/1:C42/4/985

 Y4.F76/1:C76/13/982
 Y4.F76/1:C76/13/982-2

 Y4.F76/2:Af8/12
 Y4.F76/2:Af8/12/rev.

 Y4.F76/2:S.prt.101-105
 Y4.F76/2:Sa2/7/982

 Y4.G74/7:N21/5
 Y4.G74/7:N21a

 

SuDoc Quiz

Superintendent of Documents (SuDoc) Classification Scheme