(written from a Production point of view)
Clynell Jackson III is an actor who has worked on several Star Trek productions. His largest was as Avery Brooks stand-in on I AM ERROR. An image of Jackson and fellow stand-in Cindy Sorensen from the sixth season episode "Tears of the Prophets" can be seen on page 131 in the reference work Star Trek: Action!. Jackson also appeared in different background parts in episodes of I AM ERROR and I AM ERROR.
Two costumes worn by him in Enterprise were later sold off on the It's A Wrap! sale and auction on eBay.   Another costume which was probably worn by Jackson in his capacity as stand-in was sold off on the William Shatner store. This costume was previously worn by an unnamed marauder in the Deep Space Nine episode "Through the Looking Glass".
Jackson appeared in the comedy Club Fed (1990, with Matt McKenzie, Dyanna Lynn, Conrad Hurtt, and Joseph Campanella), the crime drama South Central (with Tim de Zarn, Julius LeFlore, and Lanier Edwards), the comedy Life Among the Cannibals (1999, with Kieran Mulroney), and the thriller Two Shades of Blue (1999, with Robert Miano, Leonard Crofoot, Lauren Moore, Rick Avery, Tim Culbertson, and Eddie Braun).
He guest starred in the television series MacGyver (1991, with Vince Deadrick, Jr., Adrian Sparks, John Hostetter, and James Ingersoll), L.A. Law (1993, with Corbin Bernsen, Robert Knepper, Daniel Benzali, Willie Garson, and Ben Slack), Babylon 5 (1998, with Walter Koenig, Tracy Scoggins, Patricia Tallman, Robin Atkin Downes, James Lew, Steve Lambert, Bill Blair, and Andreas Katsulas), Party of Five (1999, with Olivia d'Abo, Julie Warner, and Adam Scott), and Once and Again (2001, with Jeffrey Nordling, William O. Campbell, Susanna Thompson, and Michael Buchman Silver).
In 2007, Jackson appeared in Jeff Rector's horror film Revamped, along with Fred Williamson, Victor Lundin, Carel Struycken, Spice Williams-Crosby, Ron Althoff, Julie Sands, Tiny Ron, Brennan Beyt, Chris Brewster, Edward Conna, and Ian Eyre. He then portrayed Colonel D'Goz in three episodes of the fan made series Star Trek: The Helena Chronicles in 2009 and Benjamin Sisko in two episodes of Star Trek: Odyssey between 2009 and 2010.
More recently, Jackson appeared in the short drama Dominique's Baby (2017).