Just a question...

It's based on the number of posts you have done in the forum

Private 0
Corporal 10
Sergeant 25
2. Lieutenant 45
1. Lieutenant 70
Captain 100
Major 150
Lieutenant Colonel 230
Colonel 350
Brigadier General 500
I have updated the forum to version 2.0.6 now.

You can see what rank each of the members have in the memberslist now. (Link at the top of the page...)