The Superintendent of Documents call number system, often called SuDoc, is used by libraries to arrange those materials received from the federal government, usually as part of the
Government Depository Program.

What departments of the federal government do you think may deal with your topic? It is important to realize that the federal government is one of the largest publishers in the world. Your topic has probably been covered by one of these publications. When you do a search in OPAL, look for government publications. They are an important resource.

A	Agriculture	J,JU	Justice
C	Commerce (Includes the Census)	L	Labor
D	Defense (Includes the CIA)	NAS	NASA
E	Energy	PR	President of the U.S.
ED	Education	S	State Department
EP	Environmental Protection (EPA)	SI	Smithsonian
FT	Federal Trade Commission	TD	Transportation
HE	Health and Human Services	VA	Veterans Affairs
HH	Housing and Urban Development	X	Congress
I	Interior (Includes National Parks)	Y	Congressional Hearings
LC	Library of Congress

After the letter indicating the agency, the SuDoc call numbers then use a combination of letters and numbers to further subdivide. Consider these examples:

D 301.82/7:H 62/3 (Air Force Roles and Missions)
L 29.16:T 84/997-98 (Foreign Labor Trends: Turkey)
Y 4.W 36:105-50 (The Future of Social Security for this generation and the next)

Unlike the Library of Congress and Dewey decimal systems, numbers in the SuDoc classification system are always treated as whole numbers. Punctuation (periods, slashes, colons) simply separate whole numbers from each other. Therefore 1.3 is shelved before 1.201.

Otterbein has been a depository library since 1966 and currently receives approximately 19% of materials that the government produces. While we are a very small depository, there are other depositories, such as Ohio State University Library and the State Library of Ohio, who have most of what is produced. We include some, but not all, of the government publications in our online catalog. The librarians can help you locate these materials.