[kgr]

If opps DBL a cue- or control bid then it is 'standard' to play:
RDBL: 1st control in DBled suit
control bid: 2nd control in DBled suit and 1st/2nd control in new suit.
 
But how do you play Pass/bid game? What about?:
Pass=Extra's and slem interest if you have not yet limited your hand. If you have limited your hand or if partner's hand is unlimited then Pass simply denies 2nd control.
 
1D-(P)-1H-(3C)
4C-(DBL)-?
- 4H=no slem interest
- Pass=not minimum (Does not deny 2nd round control, but denies 2nd control C togheter with 2nd control D)
 
2C-2D
2H-3H
3S-(DBL)
- Pass= no 2nd round control. Even if minimum, Bidding 4H is no option because partner is unmimited?
 
2C-2D
2H-3H
4C-(DBL)
- Pass= no 2nd round control C, 1st/2nd control S. Even if minimum, Bidding 4H is no option with a S control because partner is unmimited