[updated: 2020-10-10]
Players sometimes wonder where they should stand (or are permitted to stand) when a member of their own team is throwing, and when a member of the opposing team is throwing. The answer is in Article 17 (“Behavior of players and spectators during a game”). Article 17 stipulates three conditions. (In this quotation I label them a, b, and c.) While a player is preparing to throw his boule –
The opponents must stand (a) beyond the jack or behind the player and, (b) in both cases, to one side of the line of play and (c) at least 2 meters from one or the other [the jack or the player]. Only [the player’s] teammates may stand between the jack and the throwing circle.
So when a member of your own team is throwing, you are allowed to stand anywhere. You may even, if you wish, stand in the head pointing to the donnée with your toe.
The opponents, on the other hand, are much more restricted. The “line of play” [sens du jeu] is an imaginary line running through the circle and the jack. Article 17 says that the opponents are required to stay to one side or the other of the line of play. It doesn’t specify how far from the line of play, but French and Dutch national federations agree that the distance should be at least one meter. The result is this diagram, in which the opponents must stand behind the circle (in the areas marked “A”) or beyond the jack (in the areas marked “B”), at least two meters from the circle and the jack, and at least one meter to the side of the line of play.
In tournaments, the convention is for opponents always to stand beyond the jack in the “B” areas. There are potential problems with this practice. A shot boule can easily (and rapidly) fly sideways and hit the foot of a player standing in one of the “B” areas. When a player is shooting, therefore, the other players are wise to stand well away from the head. They should (if possible) stand outside the dead-ball line. Then, if a boule is shot and suddenly flies sideways, it will have gone out-of-bounds and be dead before hitting a player’s foot.
The Rules of Petanque 