Absorption system velocities, v_abs, and C IV equivalent widths versus quasar properties. From top to bottom, black hole mass, bolometric luminosity, and C IV blueshift. Golden and red stars (dots) correspond, respectively, to C IV+N V and C IV-only absorption systems from our (XQR-30) sample. Narrow absorbers and black hole properties do not show evident correlations. An interesting result is the lack of N V absorption systems at the highest bolometric luminosities.