Kostolain was a planet in or near Federation space, home to the Kostolain civilization. In the late 24th century, the Conference of Judges was an institution on the planet. The judges heard matters of protocol and law and were served by a group of ministers. Kostolain culture is noted for being highly reserved and formal. Strict protocol is always followed and, in many cases, enforced by the presence of a Protocol Master. (TNG episode: "Cost of Living")