Had the play happen tonight in our kickball game. Runners onf 1st & 2nd with nobody out.
Batter kicks an infield fly and umpire calls IF. Ball hits the ground and both runners advance and F4 throws to F6 who touches second and runner was rang up "on the force."

Umpire was pretty sure that advancing at own risk meant the force was still on. Oh well.
But now I know (and knowing is half the battle... GI Joe!)