Supplementary Details


3-suited hands

3C shows Clubs & Hearts; 3D shows Diamonds & Spades

3C & 3D are passable
3C-3D & responses 3D-3H require completion of transfer to 3H & 3S which are  passable (weak) or continue to game is a sound raise to game
3CD - 3HS is invitational (distributional)
3CD-3NT shows Hearts & Spades respectively. Maybe played in 3NT or 4Major. any other bid is showing  slam interest.
3CD-4D4C Shows double fit!
3CD-4S4H Shows both minors (rare bid as 3NT is passed over)
3CD-3D3H-3H3S-4D4C Shows the other two suits i.e. D+S C+H
3CD-3D3H-3H3S-3S4H Shows both Majors
3CD-3D3H-3H3S-4C4D Invitational

CDH (Clubs, Diamonds & Hearts)

2C Shows  Clubs and One or Two higher suits 4-4 or better
2D Shows Diamonds and one or two Majors 4-4 or better
2H Shows Both Majors 4-4 or better

Rubinsohl (2NT, 3C, 3D, 3H, 3S)

Used over 1NT and weak twos - usually a 6 card suit or very good 5 card
All Rubinsohl bids are transfers & * is a T-O
Also used after 1NT * ?
All are transfers showing 5+ card suit &  ** is a T-O showing equal length in minors asking partner to choose, while 2C & 2D are preference bids to stop.
Rubinsohl is also used after 1NT-2X-? with bids of 2N & 3-level transfers.
As above but transfer to X or indicated suit, shows 4 cards in a highest unbid major
All are transfers AND after 2NT-3C  PASS,3D,H,S are to play & promising a guard in X or its indicated suit.

1NT Overcall

Usable in all positions.
Responder must bid 2C if RHO passes, 2D is available if Diamonds is the anchor suit  OR if RHO bids: PASS or * with support for anchor suit
2 Anchor suit         To play
2H                           Promises the lowest 2 unbid suits (one of which is the anchor suit). This is a weak 2-suiter. If Hearts is one of the suits 2H may be passed.
2NT                         Promises the same 2 suits as 2H above, but is a strong 2-suiter.
2S                            Shows 14+ and the 3 suits other than the opponents opening suit
2D(if available)         2D must not be the anchor suit - when it shows a weak pre-empt. Otherwise shows a 3 suited hand with: anchor suit, Opponents suit, and highest unbid Major     
3Anchor suit             Strong (15)16+HCP, & 6+ card suit
3Opponents suit        Strong 3-suited hand (same suits as 2S above) (17)18+ HCP
3anyother suits          Strong 6+ card suit, 16+ HCP,   and 4+ cards in Anchor suit                

2C Opening: Responses
2D: 0-4 No Ace or King
2H: 1Ace or 1King or 2Kings
2S: 2Aces OR 1Ace + 1or 2Kings OR 3 or 4 Kings
2NT: 5+ No Ace or King
3NT: 5+ KC A=2, K=1
3X: No Ace or King 7 card suit
Trump Request: responses
Step 1: Jx or less
Step 2: Jxx or less
Step 3: Jxxx or less
Step 4: Qxxx or more

Control Request: responses
Step 1: No 1st or 2nd control
Step 2: 2nd round control (King or Singleton)
Step 3: 1st round control (Ace or Void)
Step 4: AK or AQ or A singleton

Interference in 2C Sequences
Before responder (NT bids included)
  1. PASS: step 1
  2. ***:  step 2
  3. Next:  step 3
  4. Next+1: step 4
Before Opener rebids (NT bids ignored)