Mean and median composite quasar spectra constructed from our golden sample (black and red curves, respectively), with the RMS scatter around the mean composite indicated by the shaded blue region. The quasar composite spectrum from Glikman et al. (2006) is plotted in magenta, the type 1 AGN composite from Euclid Collaboration: Lusso et al. (2024) is plotted in green, and the mean composite constructed using data from Landt et al. (2008, 2011, 2013) is plotted in orange. Prominent emission lines are marked for reference.