Wrong Number

[bob jenkins]

I don't really understand the confusion. It's penalized when it occurs (vs. "before the ball becomes live to start the game" or "when discovered" as in the other subsections), but it's only penalized once.

Note that if the book just changed A7's number and A7 entered and the ball became live, it's too late to penalize A7. Now, when A9 tries the same stunt, you can penalize for that.