"The U.S. Superintendent of Documents developed this system (also called SuDocs) for the arrangement of federal government publications. Arrangement is basically by issuing agency. The Documents Library uses this classification system. The Superintendent of Documents (SuDocs) classification system for publications generally groups together documents by issuing agency. SuDocs numbers consist of a letter, designating the particular issuing agency, followed by numbers identifying subordinate bureaus within the agencies and specific publications."