Density map of the RASS-Faint Source Catalogue (FSC) with XMM-Newton validation results overplotted. The source density map has been normalised by the median of the pixel density distribution. The source density directly reflects the RASS scanning strategy, with the largest exposure and source density at the Ecliptic poles. Cyan pluses (+ ): confirmed candidates associated with a BSC source. Other confirmed candidates are plotted in green, and false candidates are plotted in red. Pluses (+ ): good association with a FSC source. Crosses (× ): mis-association with an FSC source. Circles (◯ ): no association with a FSC/BSC source. Confirmed candidates with no association are mostly located in low density regions corresponding to the shallower part of the RASS survey.