ICL fraction (f_ICL) as a function of the f_ETGs. The values for the ICL obtained from VEGAS are marked in magenta and the other estimates for groups and clusters of galaxies available in the literature in black (same references as in Fig. 2). A weak trend exists between the two quantities, as indicated by the dark-red solid line, which reflects the best fit for the linear correlation. The dashed red lines mark the 1σ significance range of that correlation. The best-fit equation is f_ICL = (0.14 ± 0.08)*f_ETGs − (0.11 ± 0.06), with R² ∼ 10% and p-value = 0.12.