I just noticed that new approach charts for Sylt EDXW came out. See picture.
What caught my attention is that the LPV approaches are called RNP instead of the – so far – usual RNAV (GPS). Is that just a name change or does it have more meaning? This stuff is always pretty confusing with all those tiny little bits that allow or disallow certain things …
They are different, yet the same.
Required navigation performance (RNP) is a type of performance-based navigation (PBN) that allows an aircraft to fly a specific path between two 3D-defined points in space. RNAV and RNP systems are fundamentally similar. The key difference between them is the requirement for on-board performance monitoring and alerting.
When it comes to approaches RNAV to RNP is only a change of names.
And yet again in Germany, at Sylt the LPV DA is higher than the LNAV/VNAV one and the same as the LNAV MDA. What are they doing at DFS?
USFlyer wrote:
The key difference between them is the requirement for on-board performance monitoring and alerting.
That is actually correct! 
RNP implies performance monitoring and alerting, while RNAV doesn’t require that. The whole PBN stuff is described well from a GA perspective here: https://www.pplir.org/component/joomdoc/Public%20Files/PBN_Manual_e2.0.v3.pdf/download
Well, I am a bit confused. My soon to be installed Avidyne IFDs are not RNP approved AFAIK and I think the Gx30W as well are not RNP approved so it might very well be different in the sense that one might not be allowed to fly the approach with unapproved gear. I hope I am wrong!
So GPS was the name for approaches, no that is not good enough, they are RNAV (GNSS), no that is not good enough, RNP. Finally the FAA grew a pair and said enough is enough, we are not renaming the 13000+ approaches. In the US, they will remain RNAV (GPS). Before it is all over, ICAO will have a dozen new names that mean precisely the same thing, glad we are not playing that game any more. 
It is just renaming GPS approaches. I am sure your IFD and the Garmin boxes can fly them fine. They all have RNP APCH to my knowledge.
To complicate things the AFM supplement says it is approved for terminal arrival, departure and approach RNP procedures, go figure.
