Kappa is a Class M planet somewhere in the Alpha Quadrant, near the border between the Federation and the Tholian Assembly. It is a frequent stop for freighters.
According to a Starfleet Academy simulator scenario, Tholians accused the Federation for attacking their ships. A Constitution-class intercepted a Tholian starship as it attacked a civilian freighter. The student is supposed to prove that the Federation is not responsible for the attacks. (TOS video game: Starfleet Academy Starship Bridge Simulator)