Maybe HRH doesn't read wikipedia. In the Torygraph today he has his adornment on the right shoulder.
I think (not sure) that if they are wearing 'ceremonial' rank they do. HRH is a Marshal of the Royal Air Force but this is not an 'earned military rank'. HMQ probably gave it to him as a birthday present. I don't think it was anything to do with 3 straight spec recs
