Professional Footballers' Association chairman Clarke Carlisle has given his backing to a new Premier League crackdown on player and manager misbehaviour but warned there must be no grey areas in the new rules.
The top-flight clubs have announced a new campaign targeting "unacceptable" behaviour towards referees and criticism of officials to run alongside the Football Association's Respect campaign.
PFA chairman Carlisle, who plays for Burnley, told Press Association Sport: "As long as the guidelines are clear we will support them.
"They need to make sure there are no grey areas so that referees can apply them consistently and players know where they stand."
Carlisle said the PFA's annual meetings with the Referees' Association had shown there had been a drop in the number of incidents involving players, and claimed that when incidents did happen they were blown out of proportion.
He added: "The number of incidents where referees are accosted are becoming fewer and fewer. It is just that where incidents are highlighted they now receive massive, global attention.
"But the key is to make the guidelines clear because it can be a very emotive issue if it is subjective and incidents appear differently to different people."
Carlisle said the new crackdown was not a sign that the Respect campaign had failed.
"Respect has not failed at all," he said.
"The Referees' Association themselves have agreed the number of incidents - and the scale of the incidents - is reducing.
"It is definitely not failing but we are always looking to improve the image of the game."
The announcement by the Premier League follows a number of high-profile incidents this season culminating in Manchester United manager Sir Alex Ferguson receiving a five-match touchline ban for his television outburst at referee Martin Atkinson.
The League Managers' Association are expected to respond next week but with the proviso that more resources are dedicated to referees to improve decision-making.
Premier League chief executive Richard Scudamore said: "We do need to concentrate on the player and manager relationship with the referee this time, as every one of us knows that there have been elements of unacceptable behaviour.
"As to what we think is unacceptable; it's vitriolic abuse towards match officials and that has on occasions gone unpunished; the surrounding of referees is unacceptable; the goading of referees into trying to get opponents sanctioned we think is unacceptable; and also the undue criticism, where it spills over into questioning the referee's integrity or his honesty, is also unacceptable."