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) appointment of commodore first class has been in abeyance since 1958, leaving the pennant with a single red ball to cover all Royal Navy commodores. Modern commodores wear the sleeve lace previously worn by commodores second class. Commodore has only been a substantive rank in the Royal Navy since 1997. Before then it continued to be an appointment conferred on senior captains holding certain positions. For example, the senior commander of destroyers within a fleet in the Royal Navy could carry the title of "Commodore (D)", while the fleet's senior commander of submarines could carry the title of "Commodore (S)",