rmnka447, on 2015-December-07, 19:45, said:
They doubled 1 NT, so the transfer to ♥ is forced on any hand where you're unwilling to play 1 NTx and have a decided preference to play in ♥. It promises nothing else.
Ignoring the matter of East's double, there are different methods here after West's double. The most common is arguably that 2M shows a 3 card suit and passing shows a doubleton but it used to be that most books I saw recommended completing the transfer with a doubleton and passing to be more encouraging, the problem being that an auction such as 1NT - 2♦ - (X); P - XX; 2♥ is not terribly difficult to double when it is right to do so. So while it might promise very little, or even nothing at all, for a given partnership, for another it might be quite different. It is worth considering the idea that sometimes there are more potential methods available than you might personally be aware of.