We report on the study of MCD in resonant PE, using Gd metal as an example. When the photon energy is changed across the Gd 4d → 4ƒ excitation region, the PE-MCD spectrum varies substantially. Based on atomic-multiplet theory, we present a consistent picture of MCD in resonant 4d → 4ƒ PE and x-ray absorption at the 4d-edge, where all spectral changes can be explained by the angular-momentum of the intermediate absorption state. The present analysis shows: when tuning to a specific line of the 4d x-ray absorption spectrum with a total angular momentum J', only the associate multiplet component is found to resonate. At the ‘giant resonance’, the shape of the MCD-PE signal closely resembles the off-resonance case; this finding is explained within atomic-multiplet theory allowing a straightforward use of MCD in 4d-resonant PE (i) for element-specific analysis of multicomponent magnetic systems with high surface sensitivity and (ii) for surface-domain imaging by PE microscopy.