With the release of the Final Stand DLC back in 2014 came along the next part of the Phantom Assignments. For all 4 maps in the Final Stand DLC there would be secret premium dogtags.
A player is required to have 1 of the final stand dogtags equipped along with the other requirements in order to enter the Phantom room.
The dogtags will spawn within small boxes which spawn on the aforementioned maps and only one kind of dogtag can be found on each map, meaning the player must find a dogtag on each of the 4 maps if they wish to have all 4. However, they do not spawn instantly! The first dog tag of a round will spawn when the game clock reaches 53:00 minutes remaining. Once spawned you must search for it across the map (see the possible spawn locations below), when you find a dogtag you must use a knife on the box to open it. Be aware that you have 60 seconds after opening it to collect the dogtag before it disappears. Do not use an icicle or any weapon or vehicle on it as this will destroy it. By getting up close to the dogtag box (you may need to prone) you will get an “E” interaction option, press “E” and all players will hear a sound, the dogtag is yours! The dogtag will not appear in your solider customisation until the round finishes, this can be done by all players using the !nextmap command. You can also leave the game after you have found the dogtag but will not be awarded until the round is over. If there are other players who also need that maps dogtag, the next will subsequently spawn 7 minutes after the previous dogtag was collected or destroyed.
The dogtag boxes have 2 styles depending on which map you are on. When on Operation Whiteout or Hammerhead the dogtag boxes will be white, whilst on Giants of Karelia or Hangar 21 the dogtag boxes will be forest green with a grey lid.
With thanks to P4F for the images.
There are over 25 possible locations on each of the aforementioned maps, thankfully, a user known as _HJP_ has created maps with the exact location points in which the dogtags can spawn.