Minors 2♣♦

1♣ - 2♣ shows 5+♦ and 1♣ - 2♦ shows 5+♣, no 5-card major. A 4-card minor beside it responds 2♥ and (5332) responds 1NT, so these hands hold a 4+ major or a one-suiter with no 4-card suit. Opener relays with the next step.

With 13+, responder bids the shape at once. With 8–12, responder bids the cheapest step and, after the next relay, the same shape one step higher.

Viking 2♣♦ allow a second 4+ minor, and its opener may bid naturally instead of relaying.

Diamonds 2♣

Viking shows 6 or 7 cards before strength and resolves 6331 and 7330 to the exact shape, here and over 2♦.

Viking separates a 6-card minor with 4 in the major from one with 5, here and in the other major branches.

Clubs 2♦