Gadget of the day: Jacoby 2NT

Seriously, though, there are a couple of gadgets I think we could usefully incorporate into our bidding that might help out in some hazy situations. We all know and revere Oswald Jacoby for his famous transfers, but he devised a forcing response system too that sounds very handy.

As I understand it: Opener bids 1 of a major suit. With 12 points (some say stronger) and 4 cards in opener's suit, respond 2NT. That is considered forcing to game, and asks for a clarifying rebid from opener along the following lines:

• 3 of the initial suit: no singleton, 6 or more trumps and 18+ points, slam-hoping
  
• 3 of another suit: a void or singleton in that suit
  
• 3 no trump: no singleton or length, but 15+ points
  
• 4 of the initial suit: no singleton, no more than 14 points, limiting
  
• 4 of another suit: 5 cards in that suit
  

That seems promising to me. I guess if responder really definitely wants to play NT she can bid 3NT directly. Talking about singletons so blatantly in front of the opponents is kind of begging for an ace lead, but I wonder how it would play out in practice. Anybody up for giving it a try?