Example RVS spectra. Each spectrum is noise free and at G_RVS = 12 (i.e. with RVS in low resolution mode). The line colours are arbitrary. Three of the panels show the variation of one of the APs with the other two held constant, the constant values being T_eff = 5500 K, [Fe/H] = 0 dex, log g = 4.0 dex. [α/Fe] = 0 dex in all cases. In these cases the spectra in each panel have been offset vertically for clarity. The AP ranges (increasing from bottom to top in each panel) are: [Fe/H] = −2.5 to 0.0 in steps of 0.5 dex; log g = 0 to 5 in steps of 1 dex; T_eff ∈  {4500,5500,6500,8250,14   000,40   000} K. The bottom right panel shows examples of five emission line stars (here the offset is zero). They are, from bottom to top around the feature at 859 nm: nova; WC star; O6f star; Be star; B[e] star.