Fromtop to bottom, G, G_BP, and G_RP photometry (hereafter referred to as X) versus external photometry: CALSPEC (black dots) corresponding to X − X(calspec); HIPPARCOS (orange) residuals of the global X − Hp = f(V − I) spline; Tycho-2 (cyan) residuals of the global X − V_T = f(B_T − V_T) spline; Landolt (red) residuals of the global X − V = f(V − I) spline; and PS1 (blue) and SDSS (green) residuals of the global X − r = f(g − i) spline for SDSS and PS1. The zero point of those different residuals is arbitrary with the exception of the CALSPEC results.