Any player on a single yellow card at the end of the quarter-final stage of Euro 2008 will have it cancelled, UEFA announced on Tuesday after a two-day Executive Committee meeting.
The proposal was agreed unanimously by the committee and means that a player given a second yellow card of the competition in the semi-finals is not then suspended for the final if his team qualifies.
Previously, players had single yellow cards cancelled after the group stage so that if they picked up yellows in the quarter-finals and semi-finals they were suspended for the showpiece event.
UEFA president Michel Platini said he is delighted with the ruling.
"It is based on a footballing decision and I am happy the executive committee gave their unanimous approval for it. It means the fans should be able to see the best players in the final, as long as they do not pick up two yellow cards or get sent off in the semi-final."
UEFA also simplified its national team ranking procedure which determines each national team's coefficient.
The change should stop draws producing so-called "groups of death" in future final tournaments, such as Group C in next month's Euro 2008 tournament which comprises world champions Italy, World Cup finalists France, the Netherlands and Romania.
"The system has been simplified and is now based just on competitive matches played by a national team in the European championship or World Cup, friendlies are not taken into account," said David Taylor, UEFA's general secretary.
He said it meant that draws for the qualifying and final rounds of the European championships should now be fairer and better balanced.