What must happen before a sanction is set in netball?

In netball, before a sanction is set, the umpire must signal with a whistle. This action serves as an important cue that a rule infringement has occurred and that a sanction will be applied. The use of the whistle ensures that all players are aware of the decision being made, allowing for the game to be paused effectively. Only after the whistle has been blown does the process of addressing the infringement begin.

Positioning of the player with the ball is not a prerequisite for setting a sanction; instead, it's essential for ensuring adherence to the rules during play. Similarly, while having a minimum number of players is crucial for a valid match, it does not directly relate to the sanctioning process itself. Additionally, the ball being in play is also not a requirement before a sanction can be issued, as the umpire can call a halt to the game at any point to enforce the rules.