The point on the arrowrest that contacts the arrow.

On the rests with launcher blades, you need to be sure that you pick up or push down the launcher so that it is lined up with the arrow at full draw. My launchers tend to bend down a little when my bow is not at full draw so I have to pick it up just a little to get an accurate mark for my nock point.

On drop away rests, you also need to pick it up so that the blade is at the full draw position.