MDF of the solar neighbourhood in terms of  [Fe/H]  (upper panel) and  [M/H]  (lower panel). Continuous line refers to stars belonging to the irfm sample (5976 stars within the colour ranges of the metallicity calibration), dashed line when considering only stars fainter than M_VT = 2, dotted line to all clbr stars (8470 within the colour ranges of the metallicity calibration) and dot-dashed when applying the same luminosity cut as above. Poisson error bars are shown for a representative case in both panels.