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Course & Subject Guides

United States Government Information @ Pitt

This guide will assist you in locating and using U.S. government information.

Understanding SuDocs

The Superintendent of Documents (SuDocs) system is a classification system devised by the federal government for arrangement of their published materials. Unlike other items in the library collections, the SuDocs system groups documents together by issuing agency rather than by subject.

Focus on the Three Things You Really Need to Know about SuDocs:

  • It is not a decimal system. The number after the point is a whole number.
Decimal vs. SuDocs Order
Decimal Order SuDocs Order
D 1.1: D 1.1:
D 1.12: D 1.3:
D 1.122: D 1.12:
D 1.3: D 1.33:
D 1.33: D 1.122:


  • If the call number is the same to a certain point, then varies, the order is: Years, Letters, Numbers. Until the year 2000, the first number was dropped from years, so those years have 3 digits. Beginning with the year 2000, years will be 4 digits.
Years/Letters/Numbers Order
Example 1 Example 2
A 1.35:993 EP 1.23:998
A 1.35:R 42 EP 1.23:A 62
A 1.35:R 42/995 EP 1.23:91-44
A 1.35:R 42/2 EP 1.23:600/998-103
A 1.35:321 EP 1.23:600/R-98-23


  • If the call number stem (the numbers before the colon) has numbers slashed onto the base number, the base number comes first, followed by the slashed numbers in order. The same rule applies to numbers dashed onto other numbers or letters.

Slashes/Dashes Order
Example 1 Example 2
C 3.186: EP 1.23:
C 3.186/2: EP 1.23/A:
C 3.186/7: EP 1.23/A-2:
C 3.186/7-3: EP 1.23/2:
C 3.186/9: EP 1.23/2-2:

Common Government Agencies

A       Agriculture Department

J         Justice

C 3    Census Bureau

Ju       Judiciary

D       Defense

L         Labor

E       Energy

LC      Library of Congress

ED    Education


EP    Environmental Protection Agency

S        State Department

GA   Government Accountability Office

SI       Smithsonian Institution

HE    Health & Human Services

T 22    Internal Revenue Service

I        Interior

X, Y    Congress

I 19   U.S. Geological Survey

Y 4     Congressional Committees