As many people already know, there are ALOT of easter eggs on the map Firing Range that indicate the zombie map "Quarantaine" will be based on that map. Well the most interesting thing there is the sign that says "Gateway to Hell" and has a whole bunch of writing under. After doing a bunch of research, I finally found out what it all meant.
If you google the date April 7, 1968. It takes you to the Battle of Khe Sanh. This is where the term 2nd BN 7th CAV come in play. BN stands for Battalion and CAV stands for Cavalry. Khe Sanh is located in Vietnam and according to the date 2nd Battalion and 7th Cavalry catured the old French fort on April 8, 1968. This explains the title Quarantaine spelt in french, because this is an old abandoned french fort. Beside this is going to be another zombies map.