Fleet Investigation Agency
"To Protect and Serve"
The FIA is the Fleet intelligence arm.
Activities
Most if it is devoted to external threats, but it has an internal review department that oversees Fleet activity. In practice, FIA holds often do small covert ops, though this is ostensibly not their remit.
Departments
Fleet Intelligence
The part of FIA that concerns itself with intelligence gathering and analysis.
Confusingly, they sometimes call themselves 'FI' as well as 'FIA'.
Internal Review
Oversees issues within Fleet, and particularly between services.
Holds
FIA teams are organized into "holds" that remain together until dissolved, usually for the careers of most of the members. Teams are assigned assets (usually a corvette, if they are abroad, or an office/location if on a planet.)
These are FIA groups that have been featured in stories.