Stop short -> kiss to the head and groin. Kiss -> moderate penetration to the body (slight penetration in the dojo). These were the days before gloves and pads.
The point was not to deliver pain or damage, but to show it could have delivered damage if the attacker had wished to do so. Consider a punch to the head stopping 1 inch away with the punching arm extended 85%. This would be a point since if the attacker had fully extended, a solid hit would have resulted (he would still have to be balanced). Now if the arm was fully extended and still an inch away the attack would have had no chance of landing a solid hit and so no point would be awarded. This is how the system was originally set up.