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Superintendent of Documents (SuDoc) Classification Scheme

A guide for understanding the classification of government documents

Background and Introduction

The Superintendent of Documents Classification Scheme, abbreviated as SuDoc, is the classification and organization method for U.S. federal government publications published by the Government Publishing Office. The Federal Library Depository Program (FDLP) for disseminating government documents began in 1813, and the Government Publishing Office was created in 1861. It was not until 1895 that a standard way of organizing government publications was developed by Adelaide R. Hasse. Hasse worked as a librarian in Southern California before working for the Government Publishing Office where she was in charge of collecting, organizing, and classifying government documents.  Hasse began organizing government documents based on the agency from which the document was created. Hence, the SuDoc system organizes government documents based on which agency produces the information. 


The Government Information department in the Wells Library is a FDLP library.  Federal government materials in the Wells library Government Information department are arranged by their SuDoc designation number.

SuDoc Classification Structure

The SuDoc classification as mentioned above organizes materials by the creator of the item.  This system orders items by government agency.  Agencies are designated by an alphabetical symbol that generally aligns with the agency name.  C for Commerce Department, FT for Federal Trade Commission, I for Interior Department, and NS for National Science Foundation.  Further lists of the agency alphabetical symbols are available on the FDLP website and a helpful guide from University of Illinois libraries.

There are two basic parts to the SuDoc number.  The first part comes before the colon (:) and is called the class stem.  The second part following the colon is the book number or suffix.

Class Stem

The class stem of the SuDoc number contains the agency symbol and a number to indicate agency level.  The number 1 is used to designate publications from the parent agency.  Subagencies are indicated by numbers greater than 1 beginning with the number 2.  Following the agency designation there is a period that acts as a separation between number designations.  This is not a decimal.  The number which follows the period is the series designation.  Series designations indicate the type of the document.  

Common document types and their associated numbers include:

.1 Annual Reports

.2 General Publications

.3 Bulletins

.4 Circulars

.5 Laws

.6 Regulations, rules, and instructions

.7 Press releases

.8 Handbook, manuals, and guides

.9 Bibliographies and lists of publications

.10 Directories

.11 Maps and charts

.12 Posters

.13 forms

.14 Addresses

Book Number or Suffix

The book number or suffix follows the colon in the SuDoc number.  The book number is unique to the particular item. 

There are a few different types of items which can have differing types of book numbers.  These items include: unnumbered monographs, numbered series, and serials.

For unnumbered monographs a cutter number (letter and number combination) based on the subject is part of the suffix for the item.  The first edition does not have a year as part of the suffix, but later editions of an item will include a year in the suffix.

Numbered series include a report number in the suffix position of the SuDoc number, and similar to unnumbered monographs, a year is included for subsequent revised editions.

Serials include the volume number along with the date or a combination of years in the SuDoc suffix.

A note on years in SuDoc numbers: if the year is prior to 2000, only the last three numbers of the year are included.  For instance 1950 would be shown as 950 in the suffix.  Numbers after 2000 are included entirely in the suffix.


Government Publishing Office

For more information go to the Government Publishing Office (GPO) page and view the GPO catalog.

GPO releases an updated edition of its history book "Keeping America Informed / The U.S. Government Publishing Office / A Legacy of Service to the Nation."