Normalised spectra (black) and best fit models of the UV lines, as well as the N III-C III complex, He II λ4686, and Hα for all presumed single stars (red) and binaries (orange), ordered by increasing T_eff. The shaded areas indicate 2σ uncertainties. Black horizontal lines indicate the continuum; the continua of the different stars are plotted 1.5 normalised flux units apart for the UV lines, and 0.45 for the optical lines. Fig. 1 and similar plots for the other sources that can be found on Zenodo provide a more comprehensive overview per star.