Who said you can't find complexity in shooters?
In the 11-minute overview video (pasted in below), you will see what's required to earn this particular extra: It involves deciphering Morse Code, finding minuscule buttons hidden in the environment, and recording audio, among other things. If you can manage to complete every step, you'll receive a unique code that rewards you with an ultra-rare weapon skin and camo. It's so rare that it's typically restricted to the DICE development team!
As another incentive to pick up the game again, the free Legacy Operations expansion is available now for PlayStation 4, Xbox One and PC.
Related Game(s): Battlefield 4