Constraints for dust distributions with grain radius of the population of larger grains of a_L = 10 µm (gold), a_L = 100 µm (orange), and a_L = 1000 µm (dark red) on the HEZD parameters number ratio of larger to smaller grains N_L/N_S, total dust mass M, and relative contribution of the population of larger grains to the total dust mass M_L/M. The horizontal dashed red line denotes the case when the mass of the population of larger grains would make up half of the total dust mass (i.e., M_L/M = 0.5); for higher values of M_L/M the large grains dominate the mass budget. Constraints are computed without taking observational uncertainties into account, except for the systems HD 10700, HD 187642, and HD 203280 for which no other constraints could be derived (see Sects. 3.1 and 3.4).