(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 in Star Trek: Deep Space Nine. Images of Jackson from the sixth season finale "Tears of the Prophets" can be seen in the reference work Star Trek: Action!. Jackson played two uncredited roles in Star Trek: Enterprise: a Xindi-Arboreal technician in "The Shipment" and an Klingon in "The Expanse". The two latter costumes were 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 also guest starred in the television series MacGyver (with Vince Deadrick, Jr.), L.A. Law (with Corbin Bernsen and Ben Slack), Babylon 5 (with Walter Koenig, Tracy Scoggins, Patricia Tallman and Andreas Katsulas), Party of Five (with Olivia d'Abo and Adam Scott) and Once and Again (with Jeffrey Nordling, William O. Campbell and Michael Buchman Silver).