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Commander is the second highest line officer rank. Ranking above Lieutenant Commander and below Captain. It has a ranking code of O-5 and is equivalent to Lieutenant Colonel in the Starfleet Marine Corps. The rank insignia consists of three full pips. Officers holding the rank of Commander are generally highly respected by their peers.
The title (originally "master and commander") originated in the 18th century to describe naval officers who commanded ships of war too large to be commanded by a Lieutenant but too small to warrant the assignment of a post-captain. In practice, these were usually unrated sloops-of-war of no more than 20 guns. The Royal Navy shortened "master and commander" to "commander" in 1794; however, the term "master and commander" remained (unofficially) in common parlance for several years.
Commanders are most regularly seen as Executive Officers on starships or starbases, or as a senior Department Head. Often though, Commanders can be found as junior commanding officers in the fleet, found on various starships and, occasionally, in command of small starbases. Commanders who aren't assigned to an active duty post are often found as senior assistants in Starfleet departments on major worlds.
In Starfleet, a prerequisite to becoming a commander is by taking the Bridge Officer's Test. As commanders prove their leadership ability over time, they are considered for the difficult and highly competitive promotion to captain.
|Starfleet Officer Ranks|
|Ensign||Lieutenant JG||Lieutenant||Lieutenant Commander||Commander||Captain||Commodore||Rear Admiral||Vice Admiral||Admiral||Fleet Admiral|