The Earth Force Military tends to mix-and-match their ranks, but they're generally recognizable:
- Sinclair is a Commander
- Sheridan is a Captain
- Ivonava starts as a Lt. Commander and is promoted to Commander
- Franklin's father is a General
- Krantz is a Major
and so on. We see that Garibaldi is in EarthForce and must therefore have a rank, but he's only ever referred to as "Security Chief", which is his position.
What rank does he hold?