this is a privilege you have to buy with your milbucks.

first get 50 milbucks. post five original topics, you should have 50 milbucks.

next go to the PX. You enter by going to the link in the upper left hand corner under PX (Post Exchange)

Once there, go to the bottom choice in the list called special effects, Enter the area.

Up in the top of this areas list is the choices for avatar, signature, and finally title. Select the title. pay the milbucks. when you get the title, it shows your rank as well.

see how easy that was? :D