Players making a TV-style gesture with their hands should be given a yellow card according to Uefa.
The guidance has been given to referees ahead of VAR being introduced into the Champions League next week.
The gesture is already a bookable offence but the policy was not enforced in the World Cup last summer or other competitions where VAR is in operation.
"If players make the VAR signal and if they surround the referee, there must be disciplinary action," Uefa said.
At a briefing ahead of Uefa's congress in Rome, Uefa's chief refereeing officer Roberto Rosetti used a clip of Harry Maguire during England's World Cup match against Colombia to demonstrate when players should be booked.
The Leicester City defender made the sign believing Jordan Henderson had been headbutted.
"Where Maguire is standing making the square signal - that is a yellow card," Rosetti said. "We want action in these situations, we don't want players interfering with referee on reviews."