You need to have a rare class or better to be able to enter
Private = Rare class until level 399
Training private = level 50 to 150
Low private = level 150 to 250
Mid Private = 250 to 350
High Private = 350 to 399
Corporal = from 400 until 599
Low Corporal = 400 to 475
Mid corporal = 475 to 550
High Corporal = 550 to 599
Sargeant = from 600 until 799
Low Sargeant = 600 to 675
Mid Sargeant = 675 to 750
High Sargeant = 750 to 799
Specialist (Only gets orders from Major up can command them) = Exotic classes until level 599. Exotic classes, go here from the beginning. (They would mostly be personal bodyguards for high profile people)
Training Specialist = level 50 to 300
Low Specialist = 300 to 400
High Specialist = 500 to 599
Major - Captain = 800 - 899
Specialist Major (Only gets orders from Commanding Major up can command them) = Exodic classes level 600 to 799
Commanding Major (Can command a small army) = Rare classes over level 900, Exodic classes over level 800
Commanding Specialist (Only the commander can ask them. Yes ask.) = Legendary classes
Commander (Dean)