Difference between the measured O/Hs of z ~ 0.4 Zgals cluster galaxies (panel c)) and zCOSMOS field objects (panel d)) and the expected O/Hs from the formulations of Li13 for different infall metallicities Z₀ relative to the yield y, Z₀/y = 0.1 (enriched inflow, filled circles) and Z₀/y = 0 (pristine inflow, open circles). In addition, in panel c)) the position of cluster galaxies in the phase-space diagram (see Fig. 7) is indicated in red (blue) for accreted (infalling) galaxies. The upper histograms (panels a) and b)) for M_med objects show that in general the infalling cluster members (blue histogram) and field galaxies (panel b)) have lower metallicities, in quite good agreement with the FMR, unlike accreted galaxies (red histogram), which in general have higher metallicities than predicted by the FMR.