Any player who waves an imaginary card in an attempt to get an opponent booked will be cautioned themselves, UEFA have ruled.
Referees have also been ordered to clamp down on dissent, and to book at least one player should they be surrounded by a group.
The issue of players waving imaginary cards was highlighted on several occasions during the World Cup finals - Portugal were notable culprits during the semi-final against France.
European football's governing body issued the directive at UEFA's elite and premier referees in Nyon this week, and will come into immediate effect for this weekend's Euro 2008 qualifiers.
UEFA said they have asked the match officials to take immediate action by cautioning players in the case of the following offences:
- Waving of imaginary card to have an opponent booked.
- Crowding around the referee - at least one player should be cautioned, and not only the initiator.
- Dissent by gesture or running towards to referee.
UEFA said in a statement: 'UEFA is determined to stop dissent and the harassment of referees and wishes to make players and team officials aware that referees in all UEFA competitions will punish such confrontations on the pitch appropriately.'