Originally Posted by
Mr. Bean
Is that only in NA or can you do stopover in any country that you're originating from?
Congrats on getting that amazing routing
Short hair Francis 
I believe you are allowed 1 stopover per award ticket in any of the "gateway" cities--the city on which you first enter or leave the continent.
For example: BOS-JFK-NRT-SIN, I believe allows for a stopover in EITHER JFK or NRT, but NOT both.
Similar to
Short Hair Francis, I recently booked a BKK-NRT-JFK-SEA with a stopover in NYC. Its in Y in December, but I'm hoping J or F availability will open up. Maybe opening it up to NRT rather than HKG changes the mileage allowed, b/c YVR and SEA are quite close
Best part of that stopover is that I land JFK, but I get to depart to SEA from HPN a few days later, which is about 30 min closer to my home and avoids all that NYC tolls/traffic!