Regus V was one of the moons of Regis, located in the Oralian sector. (Star Trek: Pioneer)
In late 2382, the Tal Shiar had set up a secret listening post there. ("The Forgotten Planet")
In 2383, Major Kovok was the commanding officer of the station. Centurion Avin was sent by the Tal Shiar to assist him. ("Internal")