Metallicity distributions for NGC 1851 as derived from all four CaT-metallicity relations discussed in the text are shown in the upper panel, while distributions for the three populations we obtained from the chromosome map in Fig. 1 for the “all” calibration from above are shown in the lower panel. As for all the following, similar plots, the bars at the top of the plots show the 5–95% range of the data (lines with caps), the interquartile range (Q₁–Q₂, boxes) and medians (vertical line) for all distributions.