Trick or treat!

Every Halloween when trick or treating when you knock on someone door and say "trick or treat", if the pearson who open the door says "smell my feet" and is barefoot than everyone who knocked on the door must stop what they are doing and smell the owners feet for 15 minutes no mater who's feet they are.

The same is also true for the opposite however. If you open your door on Halloween and the trick or treater says "trick or treat, smell my feet" and shows you their bare feet than you have to spend 15 minutes smelling their feet.