XY-NT

1X  	- 1Y
1NT 	- 2C: Demands 2D. (To play 2 diamond or a limit hand. 
	    => 2D 		
		-2H	: Limit.		
		-2S	: Limit.		
		-2NT	: Limit. Denies  3433/4333		
		-3C	: Limit.	     

	-2D: Art. game forcing.		

		Further bids are natural. Bid as low as possible.		
		If partner has bid 1S, you show your 4 card heart suit before 		
		showing 3 card spade suit. 		
		If the 2D bidder bids 3 in major this is slam invitational.     

	-2H:  To play if: 1min - 1H - 1NT - 2H.     
	-2S:  To play if: 1min - 1S - 1NT - 2S.      
	-2NT: Limit.      
	-3C:  To play. Shows 6 card club suit & 4 card  major.     
	-3D:  Weak limit. Shows 6 card diamond suit & 4 card major.