Here's an interesting quote from the current FIE rules:

3. Before the beginning of each bout, the two fencers must perform a
fencing salute to their opponent, to the Referee and to the spectators.
Equally, when the final hit has been scored, the bout has not ended until the two fencers have saluted each other, the Referee and the spectators: to this end, they must remain still while the Referee is making his decision; when he has given his decision, they must again perform a fencing salute and must shake hands with their opponent, with the unarmed hand. If either or both of the two fencers refuse to comply with these rules, the Referee will suspend him/them for the remainder of the competition taking place and from the following two FIE competitions in the weapon concerned (cf. t.114, t.119, t.120). The points or titles obtained at the moment of the offence remain acquired.