Task Force Nine was a United Federation of Planets Starfleet task force deployed during the Kelvan War in 2285. (Orion Press: In Harm's Way)
Most of the vessels assigned to Task Force Nine never saw action during the war as they were defending the Federation-Romulan border.
Starfleet Command (RPG)[]
In this continuity, Task Force Nine was one of three task forces assigned to the Starfleet Third Fleet in the late 24th century.