[Manny A]

So rule 7-3-C states that the JO batter must be in the batter's box within 10 seconds after being directed to do so by the umpire. I was always led to believe that the 10-second rule applies only when the batter is first coming up to bat. But there are some who say these 10 seconds also apply between pitches.

That's not how I read 7-3-D. That's the rule requiring the JO batter to keep one foot in the box between pitches. There is nothing in the rule that says the batter is allowed to keep one foot in the box while looking at her coach for signals, and to take practice swings, as long as she doesn't exceed 10 seconds. It just says she is to keep one foot in the box, period. If she takes a full 10 seconds to step out, look at the coach, look down at her arm band, and take a couple of swings, she hasn't violated anything. 7-3-C says the 10 seconds start when the umpire directs the batter to get in the box; if he/she doesn't say anything to the batter while she's looking at her coach with just one foot in the box, the clock isn't running, correct?

Conversely, if the batter steps completely out of the box with both feet, and the umpire gives the batter a warning to keep one foot in the box, is that direction that starts that 10-second clock? I don't see that in 7-3-D. The Effect sentence says that if the batter leaves the box "and delays play", the PU can penalize the batter with a strike. To me, "and delays play" could be less than 10 seconds, could it not? If I see a batter take three or four steps out of the box and I tell her to keep one foot in, and she does it again and I remind her again, and she does it yet again for a third straight pitch, where does it say I have to wait 10 seconds after the third warning before I can rule a dead ball strike on her? I should be able to rule that strike immediately if she keeps screwing up and leaving the box, right?