the HQ of the RTB is in a rank formation called: "Chain of Command", The CoC's job is to make sure all personnel go to the lowest rank 1st then progress up one by one.
Battalion Commanding Officer, O5: The BCO is in charge of all of either 1RTB, or 2RTB, or OCS which their BCO is called Chairman (CO is the correct term but its usually Chairman) and is O6.
Battalion Executive Officer/ Vice Chairman (XO), O4 (OCS O5): The BXO is the 2nd in Command to either 1RTB, 2RTB, or OCS. Their job is to be a Assistant to the BCO and assist in duties of the BCO which is why they are key role to the Battalion structure, they are usually O4, But O5 for OCS.
Battalion Sergeant Major, E9B (SEA for OCS, Same Rank): The Battalion Sergeant Major or SEA, is the Senior Enlisted Advisor to their BCO or Chairman (Commanding Officer) if your in OCS.
(THIS IS ALL THE BATTALION STAFF U WILL NEED IN THIS PART OF HQ, RTB!)