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Government Information Research Guide

Government information tips and resources by subject and type


What does “SuDoc” mean? 

 “SuDoc” or “SuDocs” is short for “Superintendent of Documents.” The Superintendent of Documents is in charge of the Federal Depository Library Program (FDLP), the program that sends copies of government publications to libraries all over the United States and its territories. You can learn more about the FDLP here: The SuDoc classification system is used to organize publications issued by the federal government.  

There are three main things to know about SuDoc numbers.


1. Organized by agency

The SuDoc system is a “provenance-based” system, meaning that documents are organized by the agency that issues them (where they come from). So, all the Forest Service documents are together on the shelf, all Defense Department publications are together, and so on.

  The first letter of the SuDoc call number indicates the parent department. For example:


Department of Agriculture   S State Department
C Department of Commerce   SI Smithsonian
I Department of Interior   Y Congress

The next number in a SuDoc call number indicates the sub-agency that produced the publication. Using three Department of Interior agencies for example:


I 19

U.S. Geological Survey
I 20 Bureau of Indian Affairs
I 29 National Park Service


2. Whole numbers, not decimal numbers

Unlike the Dewey Decimal System, numbers in a SuDoc call number are whole numbers, not decimal numbers.Comparing the same set of numbers in the two systems you can see the difference in shelving:


Dewey 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:

3. One document, one number 

SuDoc numbers are typically assigned by a central organization, the Government Printing Office. Each document gets a unique call number, and that number should work at any other depository library that uses the SuDoc system. Therefore, if you see a SuDoc call number in another library’s catalog, on WorldCat, or in a printed reference work, check our library’s shelves—if we have it, it should be at that number.


Where did this system come from?

The foundation of the system was created by Miss Adelaide R. Hasse, while she was assistant librarian in the Los Angeles Public Library. The system was further developed in the Library of the Government Printing Office between 1895 and 1903. The system has been in use for over 100 years now and is used by most depository libraries for their government documents collections. The National Archives also uses the system to organize their copies of government publications.  

 Want to learn more?

Try the “Learning SuDocs Call Numbers” interactive tutorial: This tutorial from the Michigan State University Libraries provides more in-depth information on the system and includes a quiz and virtual shelving exercises.