Properly noting a "benched" defensive player

[wadeintothem]

As the start of the game (pregame), if a coach wants to defensively bench someone other than his DP, how should it be properly noted?


Order Position
1....... 6
2.........7
3........ 8
4........5
5........4
6 ........Not playing defense
7........3
8........DP/2
9........ 9
10........Flex/1


I've heard "10", I personally think leaving it blank is fine.

Is there a by the book way to do it?

This coach wants his flex tied to his catcher, not to the batter in the #6 spot and that is his strategy.