Minor suit bust transfer is a convention. This convention is alertable.
Minor suit bust transfer is a convention for signing off at 3♣ or 3♦ after a 1NT opening.
Convention 
Edit
To use this convention, responder should have a weak hand with at least 6 cards in either minor.
The following sequence activates this convention:
| Opener | Responder |
|---|---|
| 1NT | 2♠ |
2♠ is a puppet to 3♣, after which responder passes or correct to 3♦.
