D-4R5 was a protocol droid assigned to the Imperial garrison on M'haeli in 0 ABY. The droid was shot by Governor Grigor so that Imperial lieutenant Ranulf Trommer could use it as a cover to get close to Mora, a local repair shop owner who was suspected of being linked to the H'drachi resistance. He would later be used by the Rebel Alliance, such as decoding the encoded messages from Grigor's secret Dragite crystal mine. He stated that he was an adept at over one million different codes.