Prisoners are Duty Officers stored in your Brig. Keep them for prisoner-related Duty Officer assignments or fleet projects that specifically accept prisoners.
They are not normal active-duty officers. Their main uses are prisoner Duty Officer assignments and eligible fleet-project contributions.
Some Duty Officer assignments consume prisoners in exchange for their listed rewards. The exact assignments available depend on faction and where your character is.
If a fleet project lists prisoners as an accepted contribution, eligible prisoners from your Brig can be donated to it.
