[repsilat]

Real metric users would tell you to use millimetres instead of centimetres anyway. Powers of 1000 and all that.

(Real metric users would also spell it "centimetre", but if adopting the American spelling will expedite a changeover I think it's a fair trade.)

[andos]

A millimeter (which I rather often call “milímetro” or “millimètre”) is also too late. By the way, the SI uses powers of ten.