Having been really sad and read the Admin Instructions for both the RAF and RN the 2 Services are poles apart in their interpretation of the FRI3.
The RAF states that the recipient must have accepted PAS to be eligible whilst the RN specifically states that the FRI is for personnel who have not been offered FTCA. Indeed the RN instruction precludes anyone from accepting FTCA during the 5 Yr continuation of Service.
Either both Services are implementing it differently or one Service has got in wrong.