I can never remember the order of the shorthand property for setting the margin or padding in one declaration. That is:
margin-top: 2px; margin-bottom: 4px; m
TRouBLe is best for me. And if only 3 values are shown, it's Top, Sides, Bottom - which for UK users spells TSB (the bank the government had to bail out using our money) - so TRouBLe and TSB are closely linked!