Equivalent width diagram obtained for the spectral features of the GRB 161023A afterglow with X-shooter. It shows the strength of the lines measured for our GRB (in red) as compared to the average and standard deviation of strengths of a sample of GRB afterglows (in black), as described by de Ugarte Postigo et al. (2012b). The gray areas mask features that were not measured because they fell on telluric bands.