Substitutions

[Bandit]

I know that when I do the pre-game meeting with the coachs I look at the lineup cards count players, ck #'s, ect and then hand it back to the coaches with the statement "please ck it over one more time make sure everything is the way you want it...when you hand it back to me it will be official"...my question...when a coach make a change between innings when does the change become "official".