Officially, Fitness For Instruction.
Informally, also Fit for Infantry, Fit for Induction, Free From
Infections, Free From IPPT & so on.
As the latter concoctions infer, it's basically medical clearance
prior to partaking in an activity (or course or deployment). Unlike
those who're really reporting sick, you show up physically healthy
but can bring along any number of (civilian) documents & try to
persuade the MO not to give you a passing grade.
Reservists do a lot of FFIs, though they're generally not as a
formal as those for enlistees & ORD personnel. IPPT, overseas
exercises, when you reach age 30+ etc., the SAF will call you back
for pre-screening first.
