Asking about the bidding

During the bidding, you can only ask an opponent for an explanation

of a bid made by their side when it’s your turn to call.

And you must ask the partner of the player who made the bid, not the player who made it.

Avoid asking questions about the bidding while it is continuing,

unless you really need to know the answer in order to decide

what your next call should be (because if you then pass, your partner might draw

an inference about your strength, or your interest in the suit bid).

Otherwise, wait until the auction is finished.