Projected phase space of the galaxies of A1213, where the rest frame velocity V_rf = (V − ⟨V⟩)/(1 + z) versus the projected cluster-centric distance R is plotted. Only galaxies with redshifts in the range ±3000 km s⁻¹ are shown (black dots). The red and blue circles show the 143 members of the cluster (red and blue galaxies, as defined in the text). The giant and large red squares refer to the BCG and the pair of bright galaxies BG1 and BG2, respectively. The green curves contain the region where |V_rf| is smaller than the escape velocity (see text).