The Bilaren system was an inhabited star system which was located somewhere in the Alpha or Beta Quadrant. A planet in this system was mentioned by name on a video wall in the USS Athena in 3195. (SA: "Kids These Days")
In 2369, Amanda Rogers' adoptive parents, marine biologists in Starfleet, were posted to the Bilaren system shortly before their daughter came aboard the USS Enterprise-D. (TNG: "True Q")
This system was only mentioned in dialogue.