Comparison of the HST/STIS UV spectrum of MWC 656 (black) with reference spectra from two classes of stars: known Be+subdwarf systems (top; Wang et al. 2021) and cataclysmic variables (bottom; Pala et al. 2022; Toloza et al. 2023). The Be+subdwarf and cataclysmic variable spectra have been re-binned using bin sizes of three and two, respectively, to improve S/N. All spectra have been normalised by their median flux, and vertical offsets have been applied for readability.