Example of optical spectra of type 1 and type 2 Seyfert galaxies. Left panel: optical spectrum of a classical type 1 Seyfert galaxy: SY1 J0935+2617 (also known as SDSS J093527.09+261709.6) listed in the Turin-SyCAT where broad emission lines are clearly seen in the range 4000 − 9000 Å as indicated. Right panel: same as left panel, but for a typical type 2 Seyfert galaxy: SY2 J1135+5657 (SDSS J113549.08+565708.2), lacking broad emission lines. The main spectral emission and/or absorption features are labeled in both figures, thus providing clear examples of those spectra searched for in the literature to prepare the Turin-SyCAT.