Independent Minds, Working Together

Superintendent of Documents Classification System

In the Superintendent of Documents (or SuDocs) classification system, the call number is divided into two parts: the class number appears before the colon, and the individual book number appears after the colon.

Example: L 2.3:264
(L 2.3: is the class number, 264 the individual book number)

The first letter or letters denote the executive department or agency. The first number represents the issuing bureau, and the second number is that assigned to a particular series of publications issued by that bureau. Therefore, the call number shown above can be broken down as follows:

  • L = Labor Department
  • 2. = Labor Statistics Bureau
  • 3: = Bulletins
  • 264 = No. 264, making this Bulletin No. 264 from the Labor Statistics Bureau.

Periods, back slashes, and colons separate each section of the typical call number. Documents are shelved alphabetically by the first letter(s), and then numerically, section by section. For example, all call numbers beginning with C 1. are shelved before call numbers beginning with C 2. 

In addition, all numbers are shelved as whole numbers, not as decimals. For example,

  • HE 20.40:
  • HE 20.108:
  • HE 20.3016:

Single letters are always shelved before multiple letters (but multiple letters are then shelved alphabetically, regardless of the number of letters). For example, they would be shelved in this order:

  • L 2.3:
  • LC 4.7:
  • N 11.5:
  • NAS 1.21:
  • NS 1.2:

The numbers for Congressional commission and committee publications (beginning with Y 3. or Y 4.) have a slightly different format. The number after Y 3. or Y 4. is a Cutter number composed of letters and numbers. This number is based on an important word in the name of the commission or committee. Within the Y section, these numbers will be shelved alphabetically and then numerically by the Cutter number.

The Cutter number is often followed by a slash and then a number or numbers. The additional numbers with no dash come before the same number with a dash (followed by another number, thus adhering to the general principle that nothing comes before something in SuDocs numbers.

  • Y 4.F 49:96-89
  • Y 4.F 76/1:94-36
  • Y 4.J 89/1:98-100
  • Y 4.J 89/1-12:984
  • 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 individual book numbers are used: dates, numbers, volumes, and Cutter numbers. When used after a colon, a Cutter number is taken from an important word in the title of the document. Usually, for each class number, only one type of book number will be used. However, if both letters and numbers are used for the same class number, shelve the lettered publications before the numbered ones (letters before numbers).

  • Y 4.J 89/1:AD 65
  • Y 4.J 89/1:104/23
  • Y 4.J 89/2:C 55/2
  • Y 4.J 89/2:S.HRG.104-374
  • Y 4.J 89/2:98/52

Cutter numbers after the colon are often followed by a slash and another number or series of these. Often one of these following numbers is the date of a certain edition of the document (dates before the 21st century appear without the initial 1: e.g., 879=1879 and 989=1989). Dates after a slash are filed before numbers after a slash.

  • Y 4.AP 6/1:D 36
  • Y 4.AP 6/1:D 36/950
  • Y 4.AP 6/1:D 36/2
  • Y 4.AP 6/1:D 36/2/943