Quantities potentially associated with spurious variability in Gaia photometry. Markers are different binary types as in Fig. 1. Vertical lines correspond to the lines of constant variability significance in Fig. 1. The significance of the horizontal lines is described in the text. Duplicated sources in Gaia are indicated in the upper plot with pluses. PNe in the upper and middle plots are limited to a minimum radius of 10″ (corresponding to the selection in Fig. 1), while the lower plot has no such restriction.