SR
Assuming a European OPeration.
Bear in mind that you can not fly an RNAV route below MSA unless you are PRNAV qualified. BRNAV only allows you to operate to MSA.
PRNAV approval is a specific approval from your regulating authority which requires aircraft approval, operator approval and pilot training. I do not have the references to hand but the EuroControl web site has good sections on both BRNAV and PRNAV.
MM