A

Contemporary bar-type clasp assemblies (e.g., the RPI system) place the occlusal rest on the mesial surface of the abutment tooth; this mesio-occlusal rest helps direct occlusal forces more favorably and allows the I-bar to disengage during functional rotation, making it the standard current design [Demer, 1976, PMID 784957; Xiao, 1997, PMID 11480030].