Prior to Sydney 2000, the International Volleyball Federation (FIVB) introduced a new specialist role: the libero. This player wears a different coloured uniform from the rest of the team and can be substituted in backcourt for any player on the team. The libero cannot serve, spike the ball over the net or rotate into the front-line positions, but plays a vital role for the team in serve reception and backcourt defence. There must be at least one point played between a libero substituting off for a player and going back on the court for another player - hence he/she cannot be on the court for the whole game. The libero added an extra dimension to backcourt defence during the Sydney 2000 Games, improving the reception of teams, lengthening the rallies and giving a vital role to shorter players.