Variability–luminosity correlation obtained for f = 0.45 and β = 0.6. In addition to the 184 GRBs analysed in the present work, we also show (stars) GRBs from G05. The redshift is colour-coded. The shaded region shows a density map, obtained using a kernel density estimate, of the same data set (excluding the G05 GRBs). The four GRBs with red pentagons are long-duration merger candidates (GRB 060614, GRB 191019A, GRB 211211A, and GRB 230307A) that were considered separately.