This call is alertable.
When the opponent interfere with the 4NT Blackwood bid, if DOPI is agreed, then pass is artificial and forcing. It is technically not a bid. In this case, pass means 1 Ace (or 1 key card if playing RKCB). After passing, partner must bid again as this pass is not an intention to play in the opponent's contract.
Strong pass systemsEdit
In some bidding systems, a pass when the bidding is not opened indicates a strong hand. In this case, the partner must open the bidding if the opponent in-between also passes to prevent passing out. The pass is forcing in this case.
Consider the following bidding:
- Unusual notrump overcall, indicating at least 5-5 in the minors.
In this case, E-W are clearly sacrificing, so the pass by south does not make sense. In fact, it is a forcing pass, forcing North to either double or bid 5♥.