Highlights:

- Enlisted Starfleet officers, had not completed the four-year Starfleet Academy
- Receive basic training, along with any specific courses required for their position
- Could serve as a member of starship or space station's senior staff
- Also called Non-commissioned officer (NCO or noncom)

Ranks:

- Crewman (Able Seaman)
- Petty Officer
- Chief Petty Officer
- Senior Chief Petty Officer
- Master Chief Petty Officer
- Warrant officer-in-training
- Warrant Officer
- Chief Warrant Officer
- Master Warrant Officer
- Senior Warrant Officer