Once you reach a high enough level of coolness you are allowed to say kep. It is when the randomness thing happens, and you dont know what to say and everyone around you is silent, you say kep. It can also be used to replace normal words, but since you want to be randomn you say kep.
Jimmy: I just farted sooooo bad!
Youna: F**k you all!
James: GO TO THE OFFICE!