Chemical abundance relations for ω Cen members and APOGEE DR17 field stars. Filled black and coloured symbols represent respectively the ω Cen reference sample and the subset of field stars identified as chemically compatible with it by GMMChem. Outliers, defined as stars with a probability density below the 10th percentile threshold, are shown as empty black circles for ω Cen and as contours for field stars. The dashed line in the central panel indicates the division for our definition of Al-rich stars (see Eq. (1)).