StbyRudder,
Going with the information provided by my company(which may be different from your regulatory body) and really and extremely short summary of a few dozen pages, here goes:
if your are PRNAV approved, as stated in the limitations section of your aircraft manual, you should be able to fly procedures that have a plain RNAV in the approach header.
RNP approaches, and ICAO really messed up here because one has nothing to do with the other, have RNAV(GNSS) in the header. If the limitation section of your airplane manual states RNP APCH approved, then you can fly RNP (RNAV(GNSS)) approaches. Depending of course on your regulatory body because training and subsequent authorization is required.
RNP AR APCH, contrary as stated earlier are RNP approaches for which additional aeroplane certification and pilot training requirements are defined! They may have lower RNP values than the standard RNP APCH value of 0.3, limitations of use should be published in your aircraft manual and training manual.
Hope this helps!
Last edited by flyburg; 17th Aug 2013 at 22:27.