Aspro convention

Aspro is a contract bridge bidding convention devised by Terence Reese as a British variant on the Astro convention to intervene over a 1NT opening bid.
Like Astro, Aspro is initiated by a 2-level overcall in a minor suit when the overcaller or intervenor holds an unbalanced hand with at least nine cards in two suits, at least one of which is a major.

Subsequent bidding

The foregoing includes the possibility that the 2 overcaller holds both majors. Using Aspro with five spades and four or five hearts, the 2 bid is followed by 2 over partner's 2 or 2; with four spades and five hearts, one rebids 2 over partner's 2.