1. invitational hand
2. strong two suit hand
3. some single suit hand
4. other problem such as lead
for example:
1. partner open 2♥ show 4+♥4+♠ or 4+♥5+♣, 6-10HCP, you hold
♠xxx
♥Kxx
♦AKQx
♣Axx
2. partner open 2♦ show 4+♦4+♥ or 4+♦4+♠, 6-10HCP, you hold
♠AKxxx
♥x
♦Kx
♣KQxxx
3. partner open 2♥, you hold
♠KQ
♥x
♦AQJxxxx
♣Kxx
4. partner open 2♠, show 6+♠ or 4+♠5+♣, 6-10HCP, then
2♠ 2NT Pass 3NT
Pass all
you hold
♠x
♥KQ9xx
♦xxxx
♣AJx
how to choose your lead?
I have designed a new structure over 2♥
2♥
2♠:to sign off in minor or inv in major or inv with shortage in M, maybe a strong GF hand
2NT:balanced, inv
3♣:ask for second suit, maybe a strong GF hand
3♦:♠, GF
3♥:preempt
3♠:♦, GF
2♥ 2♠
2NT: ♠, min
3♣:♠, max
3♦:♣
2♥ 2NT
3♣:to play
3♦:5+♥ then pass=to play,3♠=55M,3NT=45M,other=6♥
3♥:5+♠ then pass=to play,3NT=54M, other=6♠
3♠:5♥5♣, maximum
3NT:to play
2♥ 3♣
3♦:♠,5+♥
3♥:♠,4♥
3♠:♣,4♥
3NT:♣,5+♥
but the structure has a big problem, it can't show a preference to play black suits. several times, we have to play 4-1 trump 2♥ at vul.

how to solve those problems?
thx
bill