Six panels compare the EW of the 1719 metallicity indicator to the EW of other absorption indexes in the FUV rest frame that were not considered in this work, either because no correlation was found with Z, or because the observational data are not in agreement with the predictions of any models (as in the case of significant ISM contamination). In each panel, we show the EW measurements from the five VANDELS stacks in stellar mass bins with colored stars (the median stellar mass of each stack is annotated in black). In addition, we superimpose EW–EW relations predicted by Starburst99 models (square symbols, with shaded gray area indicating different stellar ages from 50 Myr to 2 Gyr), and BPASS models (large circles).