Over an opening 1 or 2NT, 4D is a transfer to hearts and 4H is a transfer to spades.

After opener accepts the transfer, new bids by responder DO NOT imply a new place to play--- the partnership must play in the major except for 6NT and 7NT.

Texas Transfers are on after interference:

part opp you

1NT 2D 4H this is a transfer to spades

part you

1NT 4D

4H 4NT (Blackwood)

5H 6H