Commodore is an unofficial flag rank used when a Captain has command of two or more ships on an assigned mission; a temporary position (not a formal rank) given to a senior Post Captain and granting him authority over a ship or ships other than his own (see Admiral). Used in situations when a small squadron of ships must operate independently from the main squadron or fleet on a special mission and a commanding admiral is either unavailable or unwarranted due to the mission's scope. The position is always rescinded at the end of the mission.
When a Commodore moves from one ship to another, it is said that he has transferred his Broad Pennant.
- Commodore at Wikipedia
- Pennant image is in the public domain from Wikimedia Commons.