Patrick,
Are taking about the recess in the board for the knot in the pull-up line which goes thru a hole in the board from the inboard side.
This should be about a foot and a half down from the head of the board.
The recess is just so the knot does not jam the board when it's in the case.

I know that the voices in my head aint real,
but they have some pretty good ideas.
There is no such thing as a quick fix and I've never had free lunch!