I am also curious as to the term " His (Her) Majesty's Ship" (HMS) , as in HMS Dreadnought , for British Warships ?
Is there some precedent or custom for this , such as why not "UKS" for "United Kingdom Ship" instead, as in USS (United States Ship) in the U.S. Navy ?
There is another item which might be curious to some, that ships , mainly those used as troop transports, were designated as "USNS" (United States Naval Ship) instead of "USS" , such as the USNS General Daniel I. Sultan (TAP-120). These were ships, some of them which were formerly ocean liner passenger ships , which were used for transportation of troops below , but also had cabins topside for officers and their families. At one time these were ships of The Military Sea Transport Service (MSTS) and were manned by civilians .