(based on Roadmap : http://www.geocities.com/daniel_neill_2000/sys/ )
3♦ = game INV or slam INV 55 majors (then 3♥/♠=refuses INV, 3NT=22 majors, 4♣/♦=accept in ♥/♠)
2NT = both minors (55 weak or 54/55 INV+) or weak with diamonds
2♣ = stayman, INV or weak. with weak hand, it will just bid 2♥ over 2♦ (both majors) or pass any other answer
2♦ = GF stayman
2♥ / 2♠ / 3♣ / 3♥ / 3♠ = to play, NOT INV
3NT = to play
4♣/♦ = transfer to ♥/♠
after 1NT - 2NT, opener give preference, then responder may
pass
3♦ = to play with diamonds
3♥/♠ = notrump stopper, NOT singleton. possibly (31)(54). then opener bids 4m (passable), 3NT (passable, with stopper in the othe major), 4-other-minor=accept game, 4M=contract proposal with 5 card major.
3NT = 55 minors, NO stopper in majors, passable
4m in preferred minor = INV, passable
4 other minor = slam try