The basis for resonant photoemission and resonant inelastic x-ray scattering at core level thresholds is discussed in connection with data for a physisorption system, Ar/Pt(111), and a 3d transition metal, Ni(100). For Ar/Pt(111) the quasi-localized character of the intermediate state leads to two types of features in the autoionization spectra, showing resonant Raman and normal Auger-like behavior, respectively. For Ni(100) a resonant Raman behavior is observed both in the XES and the photoemission channels below the L3 threshold. At threshold, the emission features change character and after a rather narrow transition region they appear at constant emission energies instead. The role of probing depth effects when evaluating the RIXS data is pointed out.