Because of correlations, more than one atomic electron can change its orbital in a single photon absorption. Due to these multi-electron photoexcitations (MPEs), the atomic photoabsorption cross sections exhibit characteristic tiny spectral structures above the corresponding absorption edges. Since the atomic cross section forms a background to the structural X-ray absorption fine-structure (XAFS) signal, MPEs are a source of uncertainty in high-precision structural analysis. Resonant inelastic X-ray scattering (RIXS) can be used to isolate the MPE signal from the dominant single-electron photoionization component that contains the structural information. In this review, MPE spectral types are sorted according to the underlying physical processes and the corresponding modelling approaches are briefly mentioned. The main experimental requirements for MPE studies with RIXS spectroscopy are presented, together with a few recent examples of RIXS MPE studies on noble gases.