SCuM

SCuM is a defense against an opening 1N.

SCuM is an acronym for

Shape
Color
Major suit
(The "u" was thrown in just to make a word.)

Double = Shape = & OR &. Suit lengths and vul.: 5-5 V-NV, 4-4 NV-V, 5-4/4-5 =V.

2 = Color = & or &. Same distribution as above.

2 = Majors = &

This ends the acronym. The following bids, except for 2N, are natural(ish).

2 = 5+ in the suit bid with 2-3 of the top 5 honors.and 2+ defensive tricks.

2N = &

3 = semi=solid 5+ card suit with 2+ defensive tricks.