Cheat codes are programmed into some games by developers. As an example: Have you ever played International Super Star Soccer 64? Well this game had several codes that would unlock new teams, give the footballers giant heads and things like that. We are able to unlock these things by pressing a sequence of controller buttons at the "Press Start" screen.
But how are the cheat codes actually discovered by people who are not the game's developers? Do the developers leak them on purpose? Are they officially released? Or do 'hackers' find them while reverse engineering games?
Note that I'm not talking about Gameshark Codes - these directly edit memory addresses and thus aren't a 'cheat code' or sequence per se.
Maybe there is a secret society behind the uncovering of cheat codes and its leaking to us, merely humans?