Attack fighter 6-5 was a Starfleet attack fighter in service in the 2370s.

In 2375, attack fighter 6-5 fought at the final battle of the Dominion War. Benjamin Sisko had Ezri Dax have the ship and attack fighter 6-4 follow the USS Defiant to help the Romulans after their flagship D'ridthau was destroyed and their lines began to collapse. (DS9 novelization: What You Leave Behind)

The episode referred to attack wing 6-5 rather than an individual ship.