It’s called “Friend of the Court Brief”.
So Obama should submit his birth certificate for examination in a proceeding where the plaintiff has no standing to begin with? Or in this case, where the military is initiating the proceeding and Obama's legitimate holding of the office of president is not at issue, you're suggesting that Obama intervene by presenting his birth certificate? I'm not sure that either situation is an appropriate venue.
Would the court even accept such a “Friend of the Court Brief”? Could they rightfully accept it?