I’m working on a board that will mount in a metallic slot 2 mm wide on two edges of the board. I’ve put 3 mm keepouts on either edge, front and back, but the DRC doesn’t show failures or clearance violations between the keepouts and the pads.
In KiCad V5.1 it’s called a “Keepout Area” (Left side of screenshot) and in KiCad V5.99 it’s called a “Rule Area” (Right side) and it has a checkbox for the pads.