The fascistic counterpart to communist "Tankies" and is short for "Brown Shirt". A reference to Hitler's earliest and most fanatical supporters.
Brownies are die hard national socialists who, like the Tankies, will deny any and all negative aspects of their ideology while espousing it's merits and past glories.
Did John really say that the Aktion 4 program was an allied hoax? Stupid brownie.