C IV λ1550/C III] λ1909 line ratio (C43) as a function of metallicity (O/H, left panel) and the LyC escape fraction (right panel). The symbols have the same meaning as in Fig. 2. The colored area shows the region of C43 ≳ 0.75, where we propose that strong LyC leakers, i.e., galaxies with f_esc >  0.1, are found empirically. We note that for the sake of simplicity for comparisons with high-z studies the line ratios of the leakers are not corrected for internal reddening and could thus be slightly higher, although the corrections should be small.