Mads Mikkelsen signed an autograph on a poster. Other actors had signed the poster and put their character names and autographs on it. When Mads Mikkelsen signed it he put a name on it too. A Rebel Force Radio listener sent this in to the show:
I personally don’t feel this has anything to do with Galen Marek from The Force Unleashed. It would appear to be his character’s name in Rogue One: A Star Wars Story.