Two oddities created by this reallocation process are the current formats used by the Special Administrative Regions of the People's Republic of China, Hong Kong and Macau, both of which were returned to PRC control from Britain in 1997 and Portugal in 1999 respectively. Hong Kong's prefix of VR-H and Macau's of CS-M, both subdivisions of their colonial powers' allocations, were replaced by China's B- prefix without the registration mark being extended, leaving aircraft from both SARs with registration marks of only four characters, as opposed to the norm of five.