Players covering their mouths during confrontations with opponents could receive a red card and players who leave the field in protest at a referee's decision may be red-carded, the International Football Association Board (IFAB) said on Tuesday.
Both of the Fifa-proposed laws were unanimously approved by IFAB at a special meeting in Vancouver, Canada and will be implemented for this year's World Cup.
"As was agreed at The IFAB's Annual General Meeting (AGM) in February, these decisions follow thorough Fifa-led consultations with all key stakeholders," a statement read.
"At the discretion of the competition organiser, any player covering their mouth in a confrontational situation with an opponent may be sanctioned with a red card," it said.
Fifa president Gianni Infantino said in February that players who cover their mouths while speaking to opponents during confrontations should be sent off.
His comments came weeks after an incident in a Champions League game in which Benfica's Gianluca Prestianni was accused of making discriminatory slurs to Vinicius Jr after the Brazilian scored Real Madrid's goal in a 1–0 win in Lisbon.
The incident, in which Prestianni covered his mouth with his shirt, prompted the referee to activate UEFA's anti-discrimination protocol, halting the match.
Argentine winger Prestianni, who denied the accusation, was earlier this month handed a six-match suspension by UEFA for discriminatory conduct that was deemed homophobic.
IFAB has also acted to stop any repeat of the farcical scenes in this year's Africa Cup of Nations final in which Senegal's players walked off the pitch in protest at a potentially decisive penalty awarded to hosts Morocco.
They returned and scored a goal in extra time to win the game 1-0, although they were eventually stripped of the title in March after the Confederation of African Football's Appeal Board upheld Morocco's protests.
"At the discretion of the competition organiser, the referee may sanction with a red card any player who leaves the field of play in protest at a referee's decision," IFAB said.
"This new rule will also apply to any team official who incites players to leave the field of play. A team that causes a match to be abandoned will, in principle, forfeit the match."
