RV variation as a function of the RVS apparent magnitude (G_RVS-log (RV_PP/2)) of bright Gaia RV sources. Respective contours indicate regions of higher data concentration. A clear monotonic trend between G_RVs and log (RV_PP/2) is evident, with points well above this trend being suspected binary systems. The dashed red line marks our best-fit curve to our single star sample using Eq. A.1, while the two dotted curves mark the ±σ_s uncertainties.