To respond (e.g., after 2C opening)
1 step (2D) shows no aces
2H through 3D (steps 2 thru 5) shows that ace
2NT shows no aces, but at leats 8 HCP
3NT shows 2 aces.
A bidding convention is an agreement between two players on a different meaning of a bid in the card game bridge. These agreements are made so that partners can more quickly determine which contract, with both their cards, they can win together. Often, conventions are forged together into one, which is then called a bidding system.