Polo Rules

The ref should call out that the player needs to move on or they'll be deemed as pinning.

The trapping rule was clearly enforced in Florida by Zach as he would simply say "number six stop trapping" and you'd have about a second to move on or the whistle would go. As long as players know why whistles are blown the game remains calm and ordered IMO.

As in Rugby Union when the ref calls 'use the ball'?