Relation between gas-phase metallicity and EW(CIII]) for our sample. The dashed blue line and shaded blue region correspond to the relation found in Mingozzi et al. (2022) at low z and their observed 2σ scatter. The dashed red line is our best fit, and the observed 2σ scatter is the shaded red region. The sample is color-coded by OIII] flux when this line is detected at an S/N > 2. In the other cases, only error bars are shown.