Item Number System

  • Last Updated: August 09, 2023
  • Published: October 15, 2012

The item number system is how GPO groups materials together that are published by a government agency or sub-agency. Specific item numbers are assigned to Federal government publications that are distributed through the FDLP, and oftentimes, varying unique item numbers are assigned for specific publishing formats. An item number may be associated with a specific title and Superintendent of Documents (SuDocs) classification number or may encompass more than one publication title and classification number. To see a list of all available item numbers, review the List of Classes.

Assignment of Item Numbers

The item number assigned to a series or serial generally remains the controlling number for that series or serial, even if the title changes or if the name of the issuing agency changes.

Some agencies, such as the Fine Arts Commission and Marine Mammal Commission, have a very limited scope, and therefore only one or a few item numbers may be assigned to cover all publications issued by that agency.

When GPO confirms with the authoring agency the format(s) in which a title or series will be produced, GPO records the format(s) next to the item number in the List of Classes. Some titles have a different item number for varying formats of the same title.

Examples from the List of Classes where the format is known:

Format SuDocs Class Stem  Title  Item Number 

 Paper (P)




 AE 2.106/3: Code of Federal Regulations (P) 0572-B
 C 1.54: Bibliographies and Lists of Publications (P) 0126-A

 Microfiche (MF)




 AE 2.106/3: Code of Federal Regulations (MF) 0572-C
Y 4.F 49/20: Hearings, Prints, and Miscellaneous Publications (MF) 1013-D





D 214.32: Marine Corps Administrative Publications and Forms Electronic Library (Quarterly) (CD) 0307-A-10
L 35.26: OSHA Laws and Regulations (Quarterly) (CD) 0744-G-01





C 3.278/2: U. S. Imports of Merchandise (Monthly) (DVD) 0154-D
TD 4.79/19: Sectional Raster Aeronautical Charts (DVD) 0982-L-50

Online (EL)-




AE 2.106/3: Code of Federal Regulations (EL) 0572-B-01
GP 1.41: Government Book Talk (integrating resource) (EL) 0548-A-05

If GPO does not specify a format in the List of Classes, the authoring agency has not confirmed a format for that publication. If you select an item number with no format—or with multiple formats indicated—be prepared to accept and retain the publications in any format issued.

Examples taken from the List of Classes of item numbers with no format or multiple formats:

Format SuDocs Class Stem  Title  Item Number 

No format indicated




 D 104.2: General Publications 0351-A
I 29.9/2: Handbooks, Manuals, Guides 0648-A

 Electronic Products (miscellaneous/format unknown)(E)*




HS 8.19: Electronic Products (misc.) (E) 0520-G-06
A 98.24: Electronic Products (misc.) (E) 0074-A-15

Multiple formats






HE 20.3965: Research Monograph Series (numbered) (P/EL) 0831-C-12
HE 20.3601: National Library of Medicine Programs and Services (Annual) (P/EL) 0508-L
I 19.121: Data Series (Completely Irregular) (CD/EL) 0621-K

*E is tangible electronic format. Distribution will be in CD-ROM or DVD format.

Managing Your Selection Profile

For information on working with your item selection profile, see Amending Your Library's Selection Profile.

Online (EL) Item Numbers

Item numbers provide the foundation for most distribution and bibliographic control processes within the FDLP. GPO has traditionally applied them to print, microfiche, and tangible electronic media. In addition, GPO also applies item numbers and SuDocs classification numbers to online information products. GPO does not physically push and/or distribute online publications to the libraries. However, there are several important reasons to consider including them in a library’s selection profile. See Amending Your Library's Selection Profile for more information.

Previously Required Item Numbers

Historically, GPO required all libraries to select item numbers: 0556-C and 1004-E. These two item numbers were assigned to publications that were determined to be of significance to all depository libraries. However, as of August 2014, selection of these item numbers is no longer required and the numbers are inactive.