Histograms of A_proxy,BP/A_proxy,RP for various types of variable candidates identified in the catalogues of Gaia DR2 variables (top panel), in the ZTF catalogue of periodic variables (middle panels) and in Simbad (bottom panel; ‘Em’ are emission-line stars). Only crossmatches with Dataset C are considered. The variability type of each histogram is indicated in the upper-right corner of each panel, with the number of crossmatches available in Dataset C indicated in parenthesis next to the variability type. The thick black line in each panel represents the histogram of the full sample of crossmatches in Dataset C of the relevant catalogue. The histograms are normalized to maximum count in the top three panels, and the actual counts per bin in the bottom panel. The counts in the histogram of the full sample of Simbad crossmatches (thick black line in the bottom panel) have been divided by 300 for better visibility. The abscissa range has been limited for better visibility.