Principle

Same as for the M-openings, we can bid Swiss after a /1♣♦ - 2♣♦ (strong, inverted minor) sequence.

Rule: use all following bids (low to high) to indicate Strength (12-15 / 16-17 / 18-19) and Distribution (3-m / 4+m, 0/1  4+m, Balanced).

Note: this requires playing 5-card Major, longest minor, as we need at least 3+♣ when opening /1♣.

/1♣

- 2♣: inverted minor, 10+, 4+♣

/ 2♦: 3-♣, 12-15

/ 2♥: 4+♣, 0/1 card, 12-15

- 2 ♠: relay, start Swiss

/ 2NT: a 0-card

- 3♣: which 0-card?

/ 3♦♥♠: 0-♦♥♠

/ 3♦♥♠: 1-card ♦♥♠

/ 2♠: 4+♣, Balanced, 12-15

/ 2NT: 3-♣, 16-17

/ 3♣: 4+♣, 0/1 card, 16-17

- start Swiss

/ 3♦: 4+♣, Balanced, 16-17

/ 3♥: 3-♣, 18-19

/ 3♠: 4+♣, 0/1 card, 18-19

- start Swiss

/ 3NT: 4+♣, Balanced, 18-19

1♦

- 2♦

/ 2♥: 3-♦, 12-15

/ 2♠: 4+♦, 0/1 card, 12-15

- 2NT: relay, start Swiss

/ 2NT: 4+♦, Balanced, 12-15

/ 3♣: 3-♦, 16-17

/ 3♦: 4+♦, 0/1 card, 16-17

- start Swiss

/ 3♥: 4+♦, Balanced, 16-17

/ 3♠: 3-♦, 18-19

/ 3NT: 4+♦, Balanced, 18-19

/ 4♣: 0-card, 18-19

- 4♦: relay, which 0-card?

/ 4♥: 1-♥

/ 4♠: 1-♠