STENBERG


1H -    2NT     = GF with 4+ support.
3C/D/S          = Natural (3+ card), better than 7 losers.
3H              = Minimum.
3NT             = Void in spades.
4C/D            = Void.
4H              = Garbage minimum, mostly jacks and queens.

1H -    2NT     
3C/D -  3H      = Singleton asking bid.
        3NT     = Mildly slaminvitational, asking for A/K cuebids.
                
1H -    2NT     
3X -    3/4Y    = Singleton.
        4X      = Singleton.

                
NB:             
1H -    2NT     
3S -    3NT     = Singleton asking bid.
                

1S -    2NT     = GF with 4+ support.
3C/D/H          = Natural (3+ card), better than 7 losers.
3S              = Minimum.
3NT             = Void in hearts, maximum.
4C/D            = Void.
4H              = Void, minimum
4S              = Garbage minimum, mostly jacks and queens.


1S -     2NT    
3C/D/H - 3S     = Singleton asking bid.
         3NT    = Mildly slaminvitational, asking for A/K cuebids.
                
1S -    2NT     
3X -    3/4Y    = Singleton.
        4X      = Singleton.


COMPETITIVE BIDDING

If the enemy disturbes (bid/take-out double) after 1H/S:

* Jump-raise is preemptive (very aggressive).
* 2NT is still game force


Disturbing after 2NT:

1S - (Pass) - 2NT - (3X)

Pass    = "Normal opening", or searching for penalties. 
Dbl.    = Singleton.
3Y      = Natural, better than 7 losers.
3S      = Completely minimum.
4Y      = Without jump: natural, extra values. With jump: void.
4X      = Void.