I propose @EQ=X, @HJB=YY and @HJT=YY. I can't think of anywhere in real life where those strings would crop up. We can describe the EQ presets as a single hex character. Theoretically we could do the same for bass/treble too, but it would be unwieldy - having to map a number {-6 <= x <= 6} to { 0 ... F } isn't very user-friendly.