(1)
(2)
Traditionally, auction (1) was considered non-forcing, but encouraging, and (2) was forcing for one round (Eric Crowhurst, Precision Bidding in Acol, 1974). By the year 2000 even Crowhurst (The Acol Index) had changed his mind and both these sequences were regarded as forcing. This view is corroborated by Albert Dormer (The New Complete Book of Bridge, 1996), although both these later works suggest that responder's reverse need not show more than about 10 hcp, so presumably a minimum bid by opener could be passed.
If both these sequences show hands of about the same strength, is the concept of "responder's reverse" now obsolete? Does anyone play it as showing extra values and game-forcing? What prompted the question was the following hand which a friend bid to 6♦ using a strong club while their Acol opponents stopped in 3NT.
Should 3♦ over 2NT be forcing? How else can EW investigate slam below 3NT?