Code-16 was a protocol employed by the clone troopers of the Galactic Republic during the period of conflict known as the Clone Wars against the Separatist Alliance. After the war concluded and the Republic underwent reorganization to become the Galactic Empire in 19 BBY, the Empire sought to phase out its clone soldiers in favor of enlisted personnel, and also discontinue other elements of the Republic Military, including the Code-16 protocol. By the time that Clone Force 99 undertook their extraction mission on the planet Daro in that same year, during which they rescued the former Imperial clone commando Gregor, all codes associated with the Republic had been eliminated. This was realized by Commando Tech when he tried to initiate a Code-16 from a terminal to create a distraction, but inadvertently activated a security alarm throughout the Imperial facility, drawing the attention of TK stormtroopers.
The concept of Code-16 was first presented in "War-Mantle," the fourteenth installment of Star Wars: The Bad Batch season one, which was broadcast on July 30, 2021.