Comparison of the PSSs and CSOs with extended radio galaxies and quasars in the z − L_1.4 GHz − M_i parameter space. Left and middle columns: Projections of the distributions of the PSS-CSO sample (blue filled squares) and the extended comparison galaxies and quasars. The panels on the left-hand side show the different contributions to the basic sample from which the comparison sample is drawn (small symbols: red plus signs – Shen et al. 2011, black plus signs – Garon et al. 2019, cyan filled squares – Rafter et al. 2011, green plus signs – Kuźmicz & Jamrozy 2021, magenta filled squares – Kozieł-Wierzbowska & Stasińska 2011). In the middle column, the final ECS sample (green) is compared with the PSS-CSO sample (blue). Right column: histogram distributions of the PSSs and CSOs (blue) and the ECSs (green).