D-0T was an blue colored protocol droid used by the Galactic Republic and worked in the Senate Building Power Room during the Hostage Crisis. It's possible that D-0T was ranked as an Captain, seeing he had a white symbol on his chest that ranks Senate Commandos as Captains. D-0T, along with his counterpart, R5-S9, was destroyed by an IG-86 Droid, which continued to kill all the other droids in the power room.