another forward) who is standing close to the line-out on their side of the pitch and in a position to receive such a ball. Each team may have, at most, one receiver at a line-out. Players not forming part of the line-out, or acting as receiver, must stay at least behind the line at which the line-out is formed until the line-out is over; the only exception is if the line-out is formed within 10 metres of a team's goal-line, when they need only retreat behind the goal-line. A line-out ends when the ball, or a player carrying it, leaves the line-out, or, if a ruck or maul is formed at the line-out, when all the feet of all the players forming the ruck or maul move beyond the line of touch. The line-out was originally contested with both teams jumping unsupported to retrieve the ball. However, lifting in the line-out was legalised in 1999 under Law 18 of the World Rugby laws. Players must not interfere with the opposition during the line-out. In particular, they must not interfere with or tackle a jumper while his feet are off the ground, or interfere with players supporting him; such actions are deemed to be dangerous play and will be penalised with a penalty kick. Players in the line-out must not close the gap or enter the gap, except in the act of jumping for the ball, nor may they jump or support a jumper before the ball is thrown; such actions are penalised with a free-kick. Penalty kicks and free kicks are awarded 15 metres infield from the touch-line. If the ball is thrown beyond the 15-metre line, a player from the throwing team who is not taking part in the line-out may run forward to take the ball. If he does so, an opponent may also run forward to contest possession. Players who are taking part in the line-out may move beyond the 15-metre line as soon as the ball leaves the thrower's hands. If, however, a player runs forward or infield and the ball is not thrown beyond the 15-metre line, that player is off-side. The line-out ends when the ball crosses the 15-metre line. Players from the side not throwing may jump to compete for the ball, though they must be careful not to attract a penalty for interfering with an opposing jumper. Alternatively, they may choose not