After Prince Harry stayed down from official royal duties, sadly his nominal titles were also separated, the real mean is he is no longer authorized to wear an official military dress at free events.
In 2018, according to Hello magazine when Prince Harry and Meghan Markle were married, Queen gave permission to the Duke of Sussex to wear his “single-breasted uniform made of doeskin”.
According to the magazine which says that Captain-General of The Royal Marines, could have worn a general’s outfit, but instead chose to wear a major’s uniform, to pay tribute to his former soldiers.
By Dege & Skinner on Savile Row outfits were prudently crafted which of that his older brother Prince William also wore a matching outfit.
When Prince William married Kate Middleton, he wore the vibrant red Irish Guards Mounted Officer’s uniform also said he “opted for the military dress” too.
For service in Afghanistan, it is clear that Harry will still be entitled to wear his military medals, including his Operational Service Medal.
But having said that over the years Harry has seen dapper in many military outfits, which includes a bright-red dress uniform in March 2020 he wore for his then title as Captain-General of the Royal Marines at the Mountbatten Festival of Music.