Zurich: Players at the World Cup face FIFA disciplinary action for revealing any slogan or image on their undershirts.
Football's rules-making panel modified the law, which previously related only to political and religious statements and advertising, and agreed on Saturday it will take effect on June 1.
The panel, known as the International Football Association Board (IFAB), said breaking the rule was not a yellow-card offense, though players can be disciplined by competition organizers.
"We think it's the simplest rule for the image of the game to start from the basis that there is no room for slogans, images or alternative sponsor logos on the undershirt," said IFAB member Alex Horne, general secretary of England's Football Association.
At the 2010 World Cup final, Spain midfielder Andres Iniesta scored the winning goal then took off his shirt to reveal a statement on his undershirt dedicated to a Spanish player who died that season. That act will now lead to a probable FIFA fine in addition to a yellow card for removing the shirt.
Also, the panel rejected UEFA's proposal to remove red cards from the so-called "triple punishment" -- penalty, sending off and suspension -- for penalty-area fouls which deny a goal-scoring opportunity.
IFAB's new football and technical advisory panels will discuss the issue and oversee trials of rugby-type "sin-bins" where players are sidelined for several minutes for some yellow-card offenses.
IFAB approved head coverings for male and female players, and restated opposition to giving match officials access to video replay in decision-making.
The tougher rule on personal messages follows incidents this season when players including Didier Drogba of Galatasaray revealed tributes to Nelson Mandela on their undershirts.
Italy forward Mario Balotelli famously revealed "Why Always Me?" written on his undershirt in 2011 after scoring for his then-club Manchester City against crosstown rival Manchester United.
Still, the IFAB panel -- comprising FIFA and the four British associations -- agreed the England-proposed amendment would help avoid complications with statements having different meanings in different languages and cultures.
"It is better to say no and have a clean situation," FIFA secretary general Jerome Valcke said at a briefing after the two-hour IFAB meeting.
The triple punishment rule will return yet again to the IFAB agenda at its 2015 meeting, after several failed attempts to modify it since being introduced after the 1990 World Cup to help eradicate cynical fouls by defenders and goalkeepers.
Scotland FA chief executive Stewart Regan said the panel wanted to avoid a "flip-flop" of reverting to the old rule which allowed defenders to avoid a red card for deliberately preventing a clear scoring chance.
A European proposal to experiment with sin-bins will continue in youth football, after UEFA President Michel Platini called for different ways to punish offenders who were already shown a yellow card.
Trials in England suggested a 10-minute period on the sidelines was too long, and prompted teams to be too defensive after losing a player.
"It did have some unforeseen consequences on the flow of the game," Horne acknowledged.
The final consent for head coverings follows extra trials after a July 2012 decision to approve scarves worn by Islamic female players.
Valcke said Saturday's decision extended to male players following a request from Sikh community leaders in Canada.
The IFAB meeting in July 2012 also approved use of goal-line technology, which will remain the only use of cameras to help referees make decisions. The issue of video replay was listed for preliminary talks on Saturday's agenda.
"We can always discuss but the use of the video will not be in our game except in the goal-line technology," Valcke said.
