And that is why I'd prefer if the quoted text was: > Additionally, the higher 8 bits of ax, bx, cx and dx can be referred to as ah, bh, ch and dh. So either “

And that is why I'd prefer if the quoted text was: > Additionally, the higher 8 bits of ax, bx, cx and dx can be referred to as ah, bh, ch and dh. So either “higher” or “high” would work.