WHAT DOES BLACKHORN 209 POWDER IN STOCK MEAN?

Blackhorn powder is palms down the cleanest and greatest capturing powder which i've at any time applied! I'm taking pictures 80grn by quantity with hornady xtp 240s and they're tack drivers at 100yds! I haven't experienced a misfire using Blackhorn 209 and Winchester W209 primers!It’ll work with pellets or powder. They advise the BH209 breach pl