If there's an internal category on HMS Dolphin you would use two regular brackets (uncapitalized). Then write the word Category followed by a colon, two spaces then HMS Dolphin. Then close it with two more regular brackets. If, when showing the public view the HMS Dolphin is in red letters there either isn't a category for it or it's under a sub-category like Navy. Then you will have the search the larger military category to see if there is one already. If there is, then you will use two regular brackets, Category, colon, double space Navy comma HMS Dolphin, two regular brackets.