Run of [K/Fe] as a function of [Mg/Fe] for the six stars of NGC 1786 here analyzed (red squares). As a comparison, the same trend is plotted for the stars belonging to ω Centauri (gray and blue circles; Alvarez Garay et al. 2022) and to NGC 2808 (green triangles; Mucciarelli et al. 2015). The blue circles represent the stars of ω Cen-tauri in the same metallicity range as NGC 1786. The vertical dashed line splits the Mg-poor and Mg-rich stars. The error bar in the bottom-left corner represents the typical error associated with the abundance ratios.