Illustration of the XMM-Newton validation procedure results for a false candidate, PLCK G226.1−16.9. Top panels: sum of the emos and epn raw image (left) and reconstructed epn image (right) in the soft band. The circle of 5′ radius centred on the Planck position (green cross) corresponds to the conservative position error box. The RASS-FSC source is clearly detected (red cross) as a point source: its surface brightness profile (black points in left bottom panel) is well fitted by the XMM-Newton PSF (red line). Two extended sources labelled A and B are also detected. Bottom right panel: same as Fig. 2 for source B.