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
Captain (British Army and Royal Marines) Captain (British Army and Royal Marines) Captain (Capt) is a junior officer rank of the British Army and Royal Marines and in both services it ranks above lieutenant and below major with a NATO ranking code of OF-2. The rank is equivalent to a lieutenant in the Royal Navy and to a flight lieutenant in the Royal Air Force. The rank of captain in the Royal Navy is considerably more senior (equivalent to the Army/RM rank of colonel) and the two ranks should not be confused. In the 21st-century British Army, captains are often appointed to be second-in-command of a