Commander Mitchell B. Green was a Starfleet officer during the Dominion War.
In 2374, a file from the starship USS Nobel reported Green missing in action. (DS9: "In the Pale Moonlight")
This character was only mentioned in writing.
Green's name appeared on the casualty list
display seen on a computer readout in that episode. It is unclear whether he served on this ship or was simply reported missing by it.