2 Carreau multi : Opening 2 Coeur and 2 Pique

2♦ multi : Opening 2♥ and 2♠
These bids are used to describe a weak two-suiter. Various systems are possible : Dominique suggests :

2♥ showing a weak major two suiter 5-5 or sometimes 5-4 (but then not minimum points)
2♠ showing a weak two-suiter with 5♠ and a minor with at least 4 cards
The strength of these two-suiters varies between 4-9HCP

S	W	N	E

The bids 2♥ and 2♠ are converted to a 2♦ multicolor opening. Dominque advises that you open 2♥ with a weak major two-suiter and 2♠ with ♠ and a minor suit

Responder's bids on a 2♥ opening using the 2♦ multicolor convention
The response bid of 2NT is a forcing bid asking for info as on the opening of a 2 weak major using the SEF convention (système d'enseignement français)

With a weak and regular hand, Responder bids his best major using the law of trumps
If Game is possible, Responder bids 2NT relay to check out the best possible contract : Game or even Slam