An identifying code, which is also known as an identifying number, served as a method for the Grand Army of the Republic to tell apart and recognize individual clone troopers. This code was implanted in the left wrist of a trooper, enabling droids, for example astromechs, to connect to a specific trooper's military history stored within the GAR's database. In the initial years of the Galactic Empire, all identifying information was purged from the databases for Clone X troopers.