This is a historic (index) list of United States Army weapons and materiel, by their Standard Nomenclature List (SNL) group and individual designations — an alpha-numeric nomenclature system used in the United States Army Ordnance Corps Supply Catalogues used from about 1930 to about 1958. The explains that the "Index of Standard Nomenclature Lists (...) covers – by groups, and subdivisions of groups – all classes of equipment and supplies, assigned to the Ordnance Department for procurement, storage, issue, and maintenance."The designations in this Wikipedia list represent so-called "major items". For each of the major items, there were separate, designated "Standard Nomenclature Lists" — extensive parts catalogs for supply and repair purposes.