Oooh, forgot that one (plus I didn't count the encroachment one)
So that makes 5
• a penalty kick is kicked backwards (ball must travel forward. Backheeling is permitted provided the ball moves forward.)
• a team-mate of the identified kicker takes the kick; the referee cautions the player who...
They are laws, not rules.
There are THREE situations in which an IDFK is awarded to the defending team at a penalty.
I suggest you read up on the laws.