Understand SuDoc Numbers - Government Information - Selected Resources by Subject

What is "SuDocs"?

The Superintendent of Documents (SuDocs) system is the classification system the UNH Library and the United States government use to identify and catalog federal government publications. It was created over 120 years ago by the Government Printing Office (GPO, and now Government Publishing Office) to serve as the government's own system of classification (call) numbers. Visit the GPO's website for more information including a brief history and guidelines.

How to Read a SuDoc Number

Sample Call Number:

ED 1.102 :C 43/995

ED	The letter indicates the publishing agency. Read the letter classification in alphabetical order. Each letter or combination of letters refers to a federal agency or department, as outlined in the full list to the left. Example: ED shelved before EP.
1	The number before the period indicates the bureau or office within the agency. "1" always designates the Secretary or administrator's office, with subordinate offices beginning at "2." Read the second line as a whole number. Example: 2 shelved before 11.
.102	The number after the period indicates the various series of publication issued by the bureau or office. In this case, "102" designates the education test service series. Read the number as a whole number NOT as a decimal. Example: ED 1.11 shelved before ED 1.102
:C 43/995	After a colon, the letter "C" indicates the main word of the title (in this case, Listening to Children). "43" indicates the volume or issue number of the document. "995" indicates the publication year (1995). Years always come before letters. Example: ED 1.102:995 shelved before ED 1.102: C 43/995.
Online	Online electronic documents are labeled with the publication year plus a unique identification number. Example: ED 1.102:2001043336

NOTE: In the above example, ED 1.102 is called the Class Number (or Stem) and C 43/995 is called the the Book Number.

Source: George Mason University Libraries, U.S. Government Publications guide.