This page contains information regarding Star Trek: Discovery, and thus may contain spoilers.
In 2256, its location was labeled on the star chart "Alpha/Beta Quadrant Overview" in the ready room aboard the USS Discovery. (DIS: "Magic to Make the Sanest Man Go Mad", "The War Without, The War Within")
It was the location of a historic battle fought between the Klingons and the Romulans in the 24th century. The father of the tactics officer aboard the IKS Pagh died in battle at Tranome Sar. (TNG: "A Matter Of Honor")