The classification of late-type stars in the Uppsala system is made from photometric measurements of the criteriagandc, gmeasuring the break at the G-band andcthe cyanogen absorption. On the basis of these criteria the stars are divided into luminosity groups. Earlier only two groups, dwarfs and giants, were used. A few years ago a refinement in luminosity classification was introduced (1), the stars being divided into four luminosity groups designated d, dg, g, and c in the order of increasing luminosity. Specially the groups d and g have been defined so as to make them as homogeneous as possible. The group d corresponds to the MK luminosity group V and g approximately to the luminosity group III.