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Gov Info Basics: SuDocsBasics


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), which 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.  

The three things you really need 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 or their publication source.  For example, all the Forest Service documents are shelved 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. See three agencies from the Department of Interior in the example below:

I 19

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


2. SuDocs use whole numbers, not decimal numbers

Unlike the Dewey Decimal System, numbers in a SuDoc call number are whole numbers, not decimal numbers. The chart below compares simiiar numbers from the two classification systems to show how the publications would be located on library shelves.

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 is given a unique call number, and that number should be the same at any depository library that uses the SuDoc classification system. Therefore, if you see a SuDoc call number in another library’s catalog, on WorldCat, or in a printed reference work, if we have it, it should be at that number on the shelves in the Government Documents area in the lower level of the Merrill-Cazier Library.


Wait. Where did this system even 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 used for more than 100 years and is used by most depository libraries for their government documents collections. The National Archives also uses the system to organize its collection of government publications.  


Test your knowledge!

Think you get it?

Try the "Learning SuDocs Call Numbers" interactive tutorial from Michigan State University Libraries to test your in-depth information on the SuDoc system!