neilkaz, on 2012-March-04, 14:43, said:
Yes, or sarcastically called "blame transfer". In a good partnership, both realize it shows cards and ins't blame transfer and both realize that sometimes they will collectively still make the wrong decision and get a bad result.
North's pass of 3♥ was forcing. Thus, South's double says: I am keeping the auction open because I must not pass. I do not have spade support, a rebiddable diamond suit, or sufficient heart cards to bid 3NT.
With this knowledge, North is expected to know what to do.