Originally Posted by
MSPeconomist
However, ND and NK or RD/OD and RK/OK do appear at least on the receipt, right?
Correct.
Originally Posted by
MSPeconomist
Also, if one segment is low and one medium, I assume the booking looks like RD followed by O (rather than OD) for example, so that if I later find R, I'm already holding the O on my PNR/ticket and I can just replace the RD by an R segment to get some miles refunded. Is this right?
Also correct. Works just like a revenue ticket where the cheapest fare for the two segments is a one way in each or if you booked two RT tickets. So if you booked Q on one leg and T on another, only the one you switch, changes. Same applies for O/R/N.
However I'm not sure how mileage refunds work so I can't speak to the specifics on that part.