After partner's opening bid of one of a suit, a jump shift shows 17-18 HCP, and is made on three types of hands:
a. hands containing good support for partner
b. one-suited hands
c. semi-balanced hands
On responder's next turn, s/he (1) raises opener's suit to show type (a) hand; (2) rebids the same same to show one-suited hand and no singleton or void , or (4) bids a new suit to show support and singleton or void in the bid suit.