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SUDOC Classification System

The call number for federal government documents will differ from that used for regular books and periodicals.  Federal documents are shelved by the Superintendent of Documents system, abbreviated as SuDoc.  Unlike the regular collection (which is organized by topic), government documents are organized by agency.

SuDoc numbers always begin with a letter or letters combined with a number, then a period, then a number, then a colon.  The colon is followed by more numbers and/or letters.

The letters at the beginning of a SuDoc number represent a specific government department or agency such as:

Subagencies are assigned a number.  For instance, the Census Bureau, an agency within the Department of Commerce, is given the number 3.  So…all Census Bureau publications have SuDoc numbers that start with C 3.

Within a subagency, each series is also assigned a number.  For example, the Census Bureau’s U.S. Exports of Merchandise series is given the number C 3.278/3:.  Each individual publication in the series is then assigned a unique number or alphabetical symbol based on year, volume, series number, or title.  The unique publication number follows the colon. Therefore, C 3.278/3:2009/7 is the SuDoc number for the July 2009 issue of U.S. Exports of Merchandise.

In summary, the first half of a SuDoc number (up to the colon) identifies the agency and series, and the last half identifies the specific publication. Publications are filed alphabetically by letter and then numerically, first grouped by subagency, then by series, and finally, arranged alphabetically or numerically within each series.

Note: This is NOT a decimal system; the number after the period is a whole number.

Sudoc Tutorial

A tutorial found on the  Michigan State University Libraries site was designed to teach staff or student workers the SuDocs classification or call number system. Along with basic SuDoc information, quizzes and exercises can be found by visiting, Learning SuDocs Call Numbers.