Tarlac was a location set in the Alpha Quadrant.
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")
In 2257, during the first Federation-Klingon War, this location was occupied by the Klingons. (DIS: "The War Without, The War Within")
This location was only mentioned in writing.
might possibly have come from this location.