Maybe the Palace is better organized in these matters than anyone else.
I'm afraid I'm going to have to disagree on this one. HRH is in military uniform and is subject to the same rules and regulations as every other person wearing uniform. And the DIN, which sets out the rules and regulations for the wear of this award, clearly states when the ribbon, miniature and full size medals can be worn.
Although representing HM on an official tour, it does shall we say raise 'presentational issues' if he wants to be treated as an ordinary serviceman.