What distinguishes an RNP Authorization Required approach (RNP AR APCH) from an ordinary RNAV approach?

1. It requires specific operational authorization and demonstrated aircraft, operator, crew, and navigation-performance capability for the published procedure; it may use smaller RNP values or Radius-to-Fix legs where charted.
2. A visual approach flown with paper maps only.
3. An unguided straight-in dive through clouds.
4. A procedure requiring all aircraft to turn off terrain warning systems.