Rule to ensure indication of winner when BT-142 'winner is determined'

The codelist for BT-142 (Winner chosen) provides information on whether a winner has been determined. BT-142 is mandatory for CAN. There are three codes:

1. No competition winner has been determined and the competition is closed. (clos-nw)
2. A competition winner has not yet been determined and the competition is not yet closed. (open-nw)
3. At least one winner has been determined. (selec-w)

When the third code selec-w is selected, it should be mandatory to indicate the winner.

We suggest to define a CM rule.