Distribution of the parameters attached to the quasars without and with selections by means of the R_P/p ratio. From left to right: Galactic longitude, Galactic latitude, signed resdhift (to differentiate the northern (>0) and southern Galactic cap (<0)) and degree of linear polarization. The filled blue histogram represents the full catalog, green and red show the 30 and 40% truncation, respectively. We note the log-scale for the last plot.