Sampling of the radio flux density–X-ray flux plane with the 3HSP, Sedentary, and DXRBS samples. The blue dashed and dotted lines are the slope limits for the 3HSP sample. The black dotted line is the flux ratio that separates LBL and HBL. The green and yellow dotted lines denote the forbidden region for BL Lacs and FSRQs. The red dashed lines indicate the incomplete regions of 2WHSP.