The Kotanka system was a star system near the front lines during the first months of the Dominion War.
The Federation Second Fleet fell back past the Kotanka system in 2374 and relocated to Starbase 375 in preparation for Operation Return. Damar later informed Dukat and Weyoun of this development. (DS9: "Favor the Bold")
The Star Trek Encyclopedia (4th ed., vol. 1, p. 440) described the Kotanka system as a planetary group in the Alpha Quadrant.