[shnk]

Paul Thurston recommends starting with a negative double to show 3 card support for a major with limit+ values.
I think this means:
1♥ - 1♠ - 2♠
guarantees 4 card heart support.
and
1♥ - 1♠ - X - (2♠)
3m - P - 3♥
would be the 3 card limit raise.

Does anybody play this way?

[PhilKing]

I think it is pretty terrible advice. Two reasons off the top of my head:

1. It is bad from an information leakage perspective. Cue raise-game gives less away declarer's hand than double-new suit-limit raise-game.

2. If they jump to 3♠(or more) we are totally screwed. Partner can't bid 4♥ with, say, 14 points and 6-hearts or a 1543 with similar values. We could just punt 4♥ in the pass out seat, but that is also rather flawed.

I don't mind it on a 3343 11 count, but not as standard practice. As to differentiating between 3- and 4-card support, that is important, but most of us use 2NT as the 4+ raise, so the cue shows exactly three.

[Zelandakh]

This is a possibility in a 4 card major system but not to be recommended with 5 card majors. If you want to differentiate betrween 3 and 4 card raises (a good idea) then simply use 2NT for one and a cue for the other. You can achieve this using a transfer scheme too at the cost of some additional complexity.

[Cyberyeti]

Zelandakh, on 2013-July-15, 06:11, said:

This is a possibility in a 4 card major system but not to be recommended with 5 card majors. If you want to differentiate betrween 3 and 4 card raises (a good idea) then simply use 2NT for one and a cue for the other. You can achieve this using a transfer scheme too at the cost of some additional complexity.

Thanks Zel, saves me saying this, if you want a natural 2N, borrow 3♣.