Real World article
(written from a Production point of view)

Clark is the last name of the actor who worked as background actor on several episodes of Star Trek: The Next Generation. He appeared as a Brattain crewmember in the fourth season episode "Night Terrors" in 1991 and as a Bajoran freedom fighter in the fifth season episode "Ensign Ro" in 1991. He received no credit for his appearances and was named by the call sheet for the episodes. He filmed his scenes for "Ensign Ro" on Friday 2 August 1991 on Paramount Stage 16.