Government Publications

How to Read and Interpret the SUDOC Classification Scheme

Overview

The Office of the Superintendent of Documents, Government Printing Office, assigns call numbers to federal publications. These document "call numbers" are commonly called Sudoc numbers. They are used to designate the exact location of each document on the shelves or in the microfiche collection.

Sudocs numbers organize government publications according to the department responsible for them. The initial letter(s) of the call number represent the issuing department. There are approximately fifty, from A to Y.

For example:

A - Department of Agriculture.
I - Department of Interior.
NAS - National Aeronautics & Space Administration.
SI - Smithsonian Institute.

The number following the letter(s) refers to departmental subdivisions. Thus a "1" is always a general department, while other numbers indicate lesser divisions. Within each department, subdivisions vary. A decimal point follows this portion of the classification number.

For example:

A 1. - Department of Agriculture.
A 13. - Department of Agriculture. Forest Service.
I 19. - Department of the Interior. Geological Survey.
SI 2. - Smithsonian Institute. Bureau of American Ethnology.

The number following the decimal point indicates the type of publication or series. The first eight numbers are used consistently by all departments. Additional numbers may be used and vary from agency to agency. This portion of the classification number is followed by a colon.

For example:

SI 1.1: - Annual reports of the Smithsonian Institute.
SI 1.2 - General publications.
SI 1.3 - Bulletins.
SI 1.4 - Circulars.
SI 1.5 - Laws (agency administered).
SI 1.6 - Rules, regulations, instructions.
SI 1.7 - Releases.
SI 1.8 - Handbooks, manuals, guides.

TIP: Treat numbers on either side of the decimal "point" as WHOLE numbers when searching for federal documents.

For example:

ED 1.2
ED 1.3
ED 1.20
ED 1.21
ED 1.22

For help locating federal documents, ask a library staff member.

Following the colon an individual book number is assigned to each publication. This may be a publication's number in a series, the year the item was issued, or a Cutter number followed by additional subdivisions.

For example:

A 13.1:986 - Dept. of Ag. Forest Service. 1986 annual report.
SI 2.3:102 - Smithsonian Institute. Bureau of American Ethnology's Bulletin 102.
HE 20.8131:Ad 7 - Health & Human Services. National Institute of Mental Health. "Cutter Number" given Adolescence and Stress from the Science Reports series.

Additional Examples & Tips For Locating Federal Documents

ED 1.2:W 89
The call number for the document Displaced Workers : Implications for Educational and Training Institutions.

The letter indicates a major federal department:	Education Dept.
The number indicates an agency within a department:	"1" = the same general Dept.
The number after the decimal point indicates a series:	General publications.
The number after the colon indicates the Cutter number:	For "workers".

I 19.16:1250
The call number for the document Eruptions of Mount St. Helens.

The letter indicates a major federal department:	Interior Department.
The number indicates an agency within a department:	Geological Survey.
The number after the decimal indicates a series:	Professional Papers.
The no. after the colon indicates the exact item in the series:	no. 1250.

TIP: After the colon, letters come before numbers:
ITC 1.12:TA-406-9
ITC 1.12:7-X-21
ITC 1.12:7-20

TIP: After the colon, years come before numbers:
ED 1.2:In 8/965
ED 1.2:In 8/2

TIP: When searching the online catalog or CD-ROM Monthly Catalog, write down the entire SuDoc number before you try locating a document on the shelves or in the microfiche collection. You will not locate the document easily using only the numbers and letters to the colon.