When serving, stepping on or across the serving line as you make contact with the serve.

Failure to serve the ball over the net successfully.

 Contacting the ball illegally; (Lifting, carrying, throwing, etc.)

Touching the net with any part of the body while the ball is in play. Exception: If the ball is driven into the net with such force that it causes the net to contact an opposing player, no foul will be called, and the ball shall continue to be in play.

When blocking a ball coming from the opponents court, contacting the ball when reaching over the net is a violation if both: 

1) Your opponent hasn’t used 3 contacts. AND 

2) They have a player there to make a play on the ball.

When attacking a ball coming from the opponents court, contacting the ball when  reaching over the net is a violation if the ball hasn’’t yet broken the vertical plane of crossing over the centerline with any part of your body. Exception: if it’s the hand or foot, the entire hand or entire foot must cross for it to be a violation.

Serving out of order.

Back row player blocking (deflecting a ball coming from their opponent), when at the moment of contact the back row player is near the net and has part of his/her body above the top of the net (an illegal block).

Back row player attacking a ball inside the front zone (the area inside the 10 foot line), when at the moment of contact the ball is completely above the net (an illegal attack).