Average deviation of the measured Fe lines from the mean, as a function of wavelength. The standard deviation of the sample of stars is shown by an errorbar. The dotted lines show the 2σ interval of the scatter. Green squares are Fe I lines, while the one available Fe II line is a pale green diamond. Dark green squares are Fe I lines that deviate more than 2σ from the mean. We note that a different number of measurements goes into each point, depending on the number of stars in which the line could be measured.