Within the Outer Rim Territories' Kathol sector, a planet known as Mairne existed within the system that shared its name. This world, Mairne, was linked via hyperlanes to the nearby planets of Charis and Gandle Ott, and it sat just outside the Trition Trade Route that traversed the sector. In 8 ABY, Mairne sustained a modest colony that relied on providing ore and natural resources to Gandle Ott for its economic survival.
The DarkStryder Campaign, a 1995 addition to Star Wars: The Roleplaying Game by West End Games, included Mairne. Although Mairne itself wasn't the focus of any specific adventure, it was added to provide context about the planets in the Kathol sector. The 2009 book titled The Essential Atlas pinpointed the Mairne system, and consequently the planet Mairne, at location M-21 on the grid.