In volleyball, a carry is when a player makes contact with the ball for an excessive amount of time during a set, according to Tone Sports. The exact duration that defines a carry is a judgment call for the referee.
The referee determines whether a carry occurred by monitoring for several events. The most apparent evidence of a carry is when the player contacts the ball with the palm of the hand rather than the fingers. In a proper set, the ball should only briefly touch the player's fingers. The referee also monitors the spin of the ball as it leaves the hand; a proper set results in topspin or very little spin. Backspin often indicates excessive contact and thus a carry.