1S

Opener has about 12-16HCP, 7 or fewer losers, 1.5 defensive tricks and biddable Spades.

Suit openings follow the Canape principle; Diamonds may not be the main suit in the hand.

Responses

Canape principles apply to suit responses, so the first suit named may not be the hand's main suit.

1NT
8-10HCP; may be slightly shaded with a poor fit for opener and no biddable suit at the 1 level.
2C
Forcing

Biddable suit, 11+HCP; may not be the main suit.

May be slightly shaded with a strong rebiddable suit.

The suit may occasionally be notional (Ax or Kx) in powerful hands with a major.

2D
Forcing

Biddable suit, 11+HCP; may not be the main suit.

May be slightly shaded with a strong rebiddable suit.

The suit may occasionally be notional (Ax or Kx) in powerful hands with a major.

2S
Forcing

Biddable suit, 11+HCP; may not be the main suit.

May be slightly shaded with a strong rebiddable suit.

Raise
Direct raises are made according to the losing trick count.
2NT
11-12HCP
Jump Shift
Forcing to Game.

12-13HCP, long solid suit; a major may contain no more then one loser, but a minor may have 1.5 or 2 with compensating values.

Opener should raise on Qx or better, to prepare for cue bidding.

3NT
13-15HCP