as suggested by Ulf on http://forums.bridgebase.com/index.php?showtopic=19292

after (1♣ = natural or some balanced range) - pass - (1 ♦/♥/♠ = transfer) - ?

general rules

• double = general force, usually balanced hand (or very strong). doesn’t promise length in other suits; next X is T/O from both
• first level cue (do the transfer) = polish/raptor style. exactly 4 card other major + one minor 5+, 10-15 hcp
• 1NT = constructive overcall in bid suit. 5 + cards, 12-15 hcp. as opposed to
• 2-level-”cue” = weak overcall in bid suit, 6+cards, 9-13 hcp

full:

1C - pass - 1D (hearts) - DBL = general force, usually balanced
                        - 1H = 4 spades + 5m
                        - 1S = natural
                        - 1NT = good overcall in diamonds
                        - 2C = natural
                        - 2D = natural, but weak overcall (6+cards, 9-13 hcp)
                        - 2H = natural, 6 cards 
                        - 2S = natural, pre
                        - 2NT = 55 D+S (other suits)

1C - pass - 1H (spades) - DBL = general force, usually balanced
                        - 1S = 4 hearts + 5m
                        - 1NT = good hearts overcall
                        - 2C/D = natural
                        - 2H = weak hearts overcall
                        - 2S = natural, 6 cards
                        - 2NT = 55 D+H

1C - pass - 1S (whatever) - DBL = general force
                          - 1NT = good S overcall
                          - 2S = weak spade overcall