There is a penalty on the play.
A yellow flag means you have injured a player,foul,just like football.
It usually is called a penalty and is showed by a yellow flag.
To indicate that he has seen a penalty committed by one or more of the players.
most football officials tuck our flag in our waistband. being right handed it is tuck just to the right in front on my knickers
It indicates that a foul has been committed.
In the game of soccer, a buzzer flag is a flag attached to a buzzer worn by the assistant referee, which causes a receiver to buzz, warning the referee of the flag's use.
If the referee deems it to be delaying the restart of play or unsporting behavior.
In flag football their is a flag if you tackle.