Ranking officer
A ranking officer, also known as a superior officer, was a relative leadership position within a chain of command that one officer held over another officer or group of officers within a situational context.

Starfleet utilized this system, entrusting a ranking officer with the command decisions for various circumstances, including departments aboard a starship and leads on away missions. The ranking officer for a military unit like a starship was usually referred to as the commanding officer. The ranking officer for a duty shift on the bridge of a starship was known as a duty officer. Also, the term was occasionally used by Starfleet personnel to refer specifically to officers of a high rank. ()

Determinants for a ranking officer in Starfleet were similar to the chain of command, which included (in no particular order): rank, seniority, Starfleet division, direct orders from a flag officer or Starfleet Command, and Starfleet regulations.

Other cultures also referred to the term as more directly related to rank. In 2375, Kashyk's status as a ranking officer enabled him to take command of Devore inspection teams. ()

Examples of ranking officers
In 2151, T'Pol assumed command of the  while Captain Jonathan Archer was incapacitated, citing that she was the highest ranking officer available to Archer. ()

Lieutenant Malcolm Reed was the ranking officer of the Enterprise while Archer, T'Pol, and Commander Charles Tucker III were incapacitated. () Ensign Travis Mayweather was next in the chain of command after Lt. Reed, and ahead of Ensign Hoshi Sato. ()

T'Pol continued to be the ranking officer aboard the Enterprise after Archer in 2154. ()

In 2267, Commodore Matt Decker, the highest ranked officer aboard the  at the time, chose to enact Starfleet Order 104 and became the commanding officer before he was relieved by Spock. ()

Later in 2267, Commodore Stocker, despite his lack of field experience, was the ranking officer aboard the Enterprise and took command after the crew was infected by a radiation disease. ()

Temporarily-ranked Ensign Mendon was Wesley Crusher's ranking officer when the Benzite was aboard the  in 2365. ()

In 2370, Captain Jean-Luc Picard looked for an explanation to Cadet Crusher's defiance of orders from the ranking officer of the away team. ()

Later in the same year, Kira Nerys was the ranking officer aboard the  with Jadzia Dax. ()

In 2371, after Captain Kathryn Janeway disappeared during an away mission, The Doctor wished to speak with the highest ranking officer aboard the  who was not missing in regards to personnel changes aboard the vessel without his prior knowledge. ()

Later in the same year, Captain Janeway was concerned about making B'Elanna Torres the chief engineer aboard Voyager, as she felt that the Starfleet engineering officers might have had difficulty accepting a Maquis as their superior officer. ()

In 2374, Tom Paris reminded Torres that he outranked her when she tried to evacuate personnel from main engineering. ()

In 2376, Captain Janeway cited Regulation 191, Article 14 to pull rank on Captain Rudolph Ransom. ()

Later in the same year, Paris referred to Torres as the superior officer to crewman Mortimer Harren. ()

In 3189, Ensign Sylvia Tilly was invited by Captain Saru to become acting first officer of the  despite being only an ensign in rank. This made her a superior officer over many in terms of position, though not rank. Paul Stamets expressed that the notion of taking orders from her was both weird and disturbing. Despite this, Stamets encouraged her to accept the position and assembled a group of other officers who encouraged her to do so as well. ()

Memorable quotes
"On your feet, that's an order!"
"You can't give me orders, we're the same rank."
"I'm a bridge officer, and I have seniority."
"Yeah, by about two days!"
- Tom Paris, trying to convince B'Elanna Torres to continue moving as they traverse a cold environment within the Nyrian biosphere vessel ()

"I want you to take Seven. Since she has no rank, you clearly outrank her."
- Captain Janeway, to Ensign Harry Kim, after he expressed concern of Janeway assigning a higher-ranking officer to "his" away mission ()

"I assumed I'd be in charge during your absence, commander."
"Excuse me?"
"An Emergency Command Hologram programmed with over two million tactical subroutines outranks an ensign."
"A few words to the computer and this ensign can delete those subroutines."
- The Doctor (as the Emergency Command Hologram) and Harry Kim, discussing who will be in command of Voyager during Commander Chakotay's absence ()

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ja:首席士官
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