ok465:
Also IIRC 738 IAN can be used on an RNP (AR) approach as long as there are no RF turns involved. Many US RNP (AR) approaches have numerous transitions to a FAF on straight-in final approach, some of the transitions with RF turns (LNAV/VNAV req'd), but some with straight-in transitions (no RFs, IAN acceptable
AFAIK).
The convention for RF on RNP AR IAPs in the U.S. is to have a procedural note in the briefing strap that states "RF required" if it RF is required for all the transitions, or the final segment, or the missed approach. But, if RF is not required for the final segment or the missed approach, but only for some of the transitions, then "RE Required" will be annotated in the plan view to the beginning of that transition(s).
Unfortunately, this convention is not uniform through the rest of the world.