To assign yourself to the Bgg branch, simply make a name with the tag [Bgg], and scroll down. You'll find the forum [Bgg]. Open it up, and inside you will find the Rank list for the Bgg, as well as the Rank Sign Up Sheet. Simply record yourself as the initial starting rank, which is Bouncer (0) and Poof! You're now in the Bgg. Congratulations.
Sign up sheet's are found INSIDE the folder of the BRANCH that you are in.
Say you're in the branch CORPORATE MILITARY.
Simply scroll down to the Imperial Branches section, and click on the Corporate Military. You'll find in that folder, a list of the ranks in the military, and also a Sign up Sheet for those ranks. When you first choose the branch, or whenever you get a promotion, you sign up for that rank in the sign up sheet so we have a record of it.