PBC (Play by Commitee) is a board-forum SEIV game. So, you play as an officer of some rank or as a high-ranking civil servant (up to a System Lord, ruling over a system), within the human Empire played in this game. If you want to do *something*, you will be sending your orders to SJ, who handles the actual SEIV game.
For example, Loser is the Minister of Science and is responsible for... well, science. He has been writing quite a lot of tech reports about the discoveries of the Republic, as you can see in
this thread.