Ordnance provision system. Ordnance catalog (ordnance provision system): Group D, Gun, 90-mm, M1, and mount, gun, antiaircraft, 90-mm, T2E1, major items, maintenance parts and equipment required for maintenance of gun, 90-mm, M1. mechanism, recoil, 90-mm, T17, mechanism, recoil, antiaircraft, gun, 90-mm, M1A1, mount, gun, antiaircraft, 90-mm, T2 and mount, gun, antiaircraft, 90-mm, T2E1, addendum; Jan. 4, 1943.