"GPS or RNP 0.3 required. DME/DME RNP 0.3 NA."

I thought I had found a number without that notation, but, those may
have been "GPS" approaches, rather than RNAV.

And, the first sentence has a bit of "The Emperor has no clothes" in
it, in that it suggests there is some way of getting to RNP 0.3 in
addition to GPS. That comes from the sensor-independent concept of
RNP. Trouble is there is no sensor other than GPS around today that
will do RNP 0.3.

That sort of discrepancy is why I'm having such a hard time preparing
a sheet that clearly describes each type of GPS-based approach and
what equipment is required to fly it.

There seems to be a lot of hand-waving going on when the FAA (or
anybody else) talks about these things. Does anyone fully understand
what's going on?