It was only a matter of time before JackFrags and his merry band of Easter egg hunters found something in the Battlefield 4 Dragon's Teeth DLC. While they still haven't figured out the password to the Phantom Initiate assignment, they did find something else that veterans of the franchise will appreciate.
Tucked away on the Lumphini Garden map are two switches that, when activated, will trigger the Levolution event. Near each switch, however, are two doors that can be blown open with C4. One of the doors is just to the west of the D flag on Conquest Large, and the other one is to the east and closer to A. Once you blow the doors that are closest to the D objective, players will notice a radio sitting on the floor inside.
Here's where it gets a little bit complicated. While it still isn't known what activates the radio closest to the A flag, the one near D requires that players be wearing the Franchise Veteran Dog Tag, awarded to those who have been with the series for a long time. This can be equipped either in-game, or through Battlelog, after which point the radio will play the Battlefield 1942 theme when you interact with it.
To see the first part of this Easter egg in action, have a look at JackFrag's video down below. Do you have any idea what Dog Tag is required to activate the second radio? Let us know in the comments.