Skip to Main Content
It looks like you're using Internet Explorer 11 or older. This website works best with modern browsers such as the latest versions of Chrome, Firefox, Safari, and Edge. If you continue with this browser, you may see unexpected results.

Guide to Interpreting SuDoc Classification Numbers

Tips for locating US Government Publications shelved using the Superintendent of Documents Classification System

Tips for Congressional Materials

SuDoc numbers for Congressional commissions and committees (Y3. or Y4. respectively) have a slightly different format.  The number following the Y3. or Y4. is a Cutter number composed of letters and numbers.  These documents will be shelved alphabetically and then numerically by the Cutter number.

In many cases, the Cutter number is followed by a slash and one or more numbers.  The additional numbers with no dash come before the same number with a dash.

        Y 4.F 49: 96-89 

        Y 4.F 76/1: 94-36

        Y 4.J 89/1: 98-100

        Y 4.J 89/2: 99-10

        Y 4.J 89/2-10: 984

        Y 4.J 89/2-11: 979


After the colon, several types of book numbers are used: dates, numbers, volumes, and Cutter numbers.  Usually only one book number is used. However, if both letters and numbers are used for the same class number, the lettered documents will be shelved before the numbered ones.

      Y 4.C 73/7: AD 65

      Y 4.C 73/7: 104/24

      Y 4.C 73/8: M 55/2

      Y 4.C 73/8: S. Hrg. 105-65

      Y 4.C 73/8: 97/16

Tips for Annual Reports

Annual publications are indicated by a slash and a three digit number (dates in the 1800's and 1900's are indicated by the last three digits of the year. Ex. 1879=879 and 1989=989) after the book number. Dates after a slash are filed before numbers after a slash.

C 3.6: PR 8

C 3.6: PR 8/997

C 3.6: PR 8/2

C 3.6: PR 8/2/997

Complete Shelving Rules

The Government Publishing Office provides a complete explanation of the Superintendent of Documents Classification System.