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
Lieutenant (British Army and Royal Marines) Lieutenant (British Army and Royal Marines) Lieutenant (; Lt) is a junior officer rank in the British Army and Royal Marines. It ranks above second lieutenant and below captain and has a NATO ranking code of OF-1 and it is the senior subaltern rank. Unlike some armed forces which use first lieutenant, the British rank is simply lieutenant, with no ordinal attached. The rank is equivalent to that of a flying officer in the Royal Air Force (RAF). Although formerly considered senior to a Royal Navy (RN) sub-lieutenant, the British Army and Royal Navy ranks of lieutenant and sub-lieutenant are