Examples of the star-by-star correlation between the gravity difference and the published abundances (left panel). The same correlation is shown in the right panel after source ZP corrections. For an easier visualization, vertical shifts were applied together with a factor of two decrease of the [Fe/H] ranges (including the slope of the fitted straight line with an original value of −0.25). Numbers at the individual objects show the RMS values around the straight lines). See text for further details.