All this chat about hats, saluting, rank etc. brings the following story to mind.
An Army Captain was walking along the road of a RAF Station, a Ch/Tech walking in the opposite direction gave the Captain a smart salute whereupon the Captain (intrigued by the upside down stripes) stopped the Chief and asked what was his rank. When told he said 'What would have been your rank had you been in the Army'?
'Brigadier sir' came the quick response.
True I swear