Watch out, you JJ2 geeks!

I just recently played the original levels again and wondered, who Mark was. To explain my concern: In the first level of the episode 'Flashback' there is a sign saying: 'Mark wears briefs.' Of course Mark's someone from the programming-team or whatsoever, but does anyone know his exactly position in the whole producer-team? I'm just curious and at least someone should know it.