Template:Blender 3D: HotKeys/3D View/Edit Mode/CTRL-RKEY
CTRL+RKEY — (editing mesh) loop cut: move mouse to choose orientation, LMB to proceed to position new loop: then PKEY to toggle percentage/proportional mode, FKEY to toggle opposite vertex marker (proportional mode only), LMB to accept, MMB to accept and position at halfway point, RMB to cancel. (Editing armature) roll bone