A rare convention whereby responses of 3♥ and 3♠ (and optionally 3♦ after 1♣) to an opening bid of one of a minor show good trump support, sound values for at least 3NT and some slam interest.
The convention has the advantage that responder can show his support and values without taking the bidding beyond 3NT. You may use the Swiss response to show a strong holding in the suit bid or to show specific hand-types.