PKS 0023–26: Upper panel: UVB+VIS Nuclear spectrum (black solid line) and best-fit model (red solid line) for the continuum emission, regions of the spectrum corresponding to masked emission lines are indicated in blue. Lower panel: residual spectrum after subtraction of the stellar continuum showing the emission lines associated with the warm ionised gas. Wavelengths are plotted in Å, and the flux scale is given in units of 10¹⁷ erg s⁻¹ cm⁻² Å⁻¹. We note that plots with detailed fits to the emission lines in this source are presented in the main text.