A long time ago, in a land not so far away, Dupont, through its subsidiary arm, C.I.L. (name changed from C.X.L.) built an explosives plant in Quebec to supply energetics (neat word for propellants & explosives). DuPont much later became IMR (exclusive distribution by Hodgdon) but the plant is now owned by General Dynamics.
4895 was used in a few military calibers, like the .30 U.S. Springfield. There was no alphabet soup at the beginning of the name, because Hodgdon (who bought a whack of it from the military after the Second World War, was the only place you could get it. Same with all of the single-base stick powders being sold in the 50's. Then DuPont started selling new manufactured powders; enter IMR 4895, amongst others. Hodgdon then called his powders H-4895.
Before Hodgdon got the exclusive distribution rights for Quebec-manufactured powders, he went to Australia Defence Industries to get N.A. powder distribution rights for their powders. Before that, Nobel in Scotland made their powder, then Bofors in Sweden made it. Now new H4895 (ADI 2206H) is different from original 4895 (U.S. surplus), DuPont's IMR 4895, Hodgdon's later Scotland-made H4895, still later Sweden-made H4895, later-again Quebec-made H4895 & newer still Australian-made H4895.