Air commodore is never shortened to Commodore, which is a rank in various naval forces. Air commodore is a one-star rank and the most junior air officer rank, being immediately senior to group captain and immediately subordinate to air vice-marshal. It has a NATO ranking code of OF-6 and is equivalent to a commodore in the Royal Navy or a brigadier in the British Army or the Royal Marines. Unlike these two ranks, however, it has always been a substantive rank. Additionally, air commodores have always been considered to be air officers whilst Royal Navy commodores have not since the Napoleonic Wars
Commodore (Royal Navy) 1734 the title of commodore was formally approved by an order in council.. They were formally separated into first class (those with subordinate line captains) and second class (those commanding ships themselves) in 1826. The previous broad red and blue pennants were abolished in 1864 along with the coloured squadrons, the commodore of the white's broad pennant with the Cross of St George remained as the command flag for commodores first class, who wore the same sleeve lace as rear admirals. The white broad pennant with a red ball was introduced as the command flag for commodores second class. The