After direct X,Stayman and major suit transfer are on. Redouble asks opener to bid 2§.

Same applies after 1NT overcall of a minor, but

 

(1♥) 1NT (X) XX = minor one suiter

                        2C = C + S

                        2D = D + S

                        2H = xfer

           

(1) 1NT (X) XX = minor one suiter

                        2C = C + H

                        2D = D + H

                        2H = natural

 

           

1NT (P) P (X)

P      (P) XX = minor one suiter

                        2C = C + another

                        2D = D + another

                        2H = H + S