What are the serving rules in beach volleyball?

Under Rule 12:

• The 1st referee whistles to authorise the serve. You then have 5 seconds to hit it (indoor allows 8).
• Hit the ball with one hand or any part of the arm, after tossing or releasing it. Only one toss or release is allowed. Moving the ball in your hands beforehand is fine.
• If you toss or release the ball and it lands without you touching or catching it, that counts as your serve, and no further attempt is allowed.
• You may move freely in the service zone. At the moment of the hit, or take-off for a jump serve, you must not touch the court (the end line included) or the sand outside the service zone, and your foot may not go under the end line. If sand you push moves the line, that isn't a fault.
• A serve made before the whistle is cancelled and repeated.
• Screening: your partner may not stop the opponents seeing the serve and the flight of the ball.

Serving faults give the opponent a point and the serve: serving out of order, an improper serve, or a ball that touches your partner, fails to cross the net through the crossing space, goes out or passes over a screen. Opponents may not block your serve.