Officially recognised (10)
(Other definitions for accredited that I've seen before include "Certified officially" , "Given official recognition" , "Given official authorisation" , "Broadcast" .)
'officially recognised' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for formal that I've seen before include "Regular" , "Ceremonial or official" , "according to protocol" , "Essential" , "Official - conventional" .)