A little trial and error, and I think I figured it out: - m = margin on all sides - mt = margin top - mb = margin bottom - ml = margin left - mr = margin r

A little trial and error, and I think I figured it out: - m = margin on all sides - mt = margin top - mb = margin bottom - ml = margin left - mr = margin right - mx = margin on x axis (left & right) - my = margin on y axis (top & bottom)