|  | SIGNALLING CANCEL CALL |

If we wish to alter a decision that has been made, we can cancel the call by touching each shoulder with the opposite hand. It doesn't happen very often.
I think I've seen it just a couple of times in my career, thankfully not by me because it means a mistake has been made.
I probably ought to have used it a couple of times, but, as yet, I still haven't called that.