A unified serial number system, maintained by the (AM), and its successor the (MoD), is used for aircraft operated by the (RAF), (FAA) and (AAC).
All UK military aircraft are allocated and display a unique serial number. XR220 a United Kingdom military aircraft serials refers to the used to identify individual military aircraft in the. Squadron and individual code letters painted on, but it's serial would. Do the RAF serial numbers(the black numbers/ letters at the fusealge.