Which action is not permitted while receiving a serve?

When receiving a serve in volleyball, certain actions are regulated to maintain fair play. A key rule is that players cannot reach over the net to interfere with the serve or the play. This is because reaching over the net can obstruct the opponent's attempt to serve and could lead to safety issues. The server’s area must remain clear, ensuring that they can serve without interference.

On the other hand, players do not necessarily have to stand at the back line when receiving a serve. They can position themselves anywhere on their side of the court within their designated area. Players must also maintain their positions prior to the serve but can move once the ball is in play. Finally, touching the net during the reception of the serve is not permitted as it could be seen as an interference call.

Thus, the rule against reaching over the net reinforces the integrity of the serve and protects both teams during this critical moment of play.