In a military, an officer referred to an individual who commanded soldiers but did not engage in fighting.
After the initial failures of the New Dalek Paradigm, the Prime Minister of the Daleks made the Type IX Dalek casing into an officer class, having the military active units return to the Type VIII design. (PROSE: Dalek: The Astounding Untold History of the Greatest Enemies of the Universe)
When Danny Pink met the Twelfth Doctor, he compared the Time Lord's attitude to that of an officer. (TV: The Caretaker) Upon having an epiphany about his morality, the Doctor made a point of telling Danny that he was not an officer. (TV: Death in Heaven)