In a similar way to the game of Safety/Doorknob for farts, then Window Pane is called when a friend burps within earshot. You are then entitled to punch them until they touch a window pane.
In order to protect oneself from being punched, you can call Security or just say a simple "Excuse Me".
Other derivatives of Safety/Doorknob include Tent Zipper, and numerous others I can't think of right now that are more appropriate to a particular situation.
Spencer: Window Pane!
(Spencer beats the crap out of Josh, until Josh stands up - especially amusing in class - and touches a window pane)