Italian abbreviation for the square meter (metro quadrato). Similarly, cmq is a square centimeter and kmq is a square kilometer. These are non-standard symbols; the correct symbol for the square meter is m2
Russ Rowlett (Director), How Many? A Dictionary of Units of Measurement, Center for Mathematics and Science Education University of North Carolina, USA 2005. http://www.unc.edu/~rowlett/units/dictA.html, (Unit of Meas and Covr Factors - Amer) {608}