I with None on this one...there is far too much disinformation here.....
One could go on for pages on requirements, BUT...
As for documentation: The only source you should use is your respective OpsSpec. This and only this, will give all of the particular guidance, as there can be waivers, exemptions, and such. You may only have the spec for .3 RNP, even though the charts and FMS equipment show .1 RNP is available...
and the equipage requirements build upon each other, so its not if/then...its if/if/then/if/and only if/then
I will add this quickly on charts, RNP in particular.
The chart shows Glide Path Angle, the default criteria design is 3 degrees..
The chart will note if this is not ILS coincident.
RNP designs are currently uncompensated baro based for vertical. The low temperature limits shown on the charts is where the design GPA of 3 degrees hits 2.71 degrees...
The original question noted P-RNAV(GNSS) ...you need GPS to use this, currently, the governing bodies require at least 2 operational GPS to use a procedure.
For Oceanic RNP-10, I believe only one GPS unit is required, and your inertial drift time must be able to keep it in this bound.