Its a game:

When someone burps, they have to shout out sholtz, and then extend the thumb and pinkie finger (and make a fist with the middle three) then put the hand to their forehead, with the thumb touching the forehead.

Whoever is last to do this out of the gaming group gets hit very hard.

this is a game.. when it is at a slient/awakard moment you slap a person near by on the head... but you can block this by placing your hand on your forehead. And if you succed in this block you get to punch that person in the arm!