Scenario 1:  A pilot launches from McKenzie launch and flies southeast, towards the airport (the black line below).  At the south end of the range the pilot turns around, and flies northwest along the range (bypassing launch) to Copperdome (the red line below).  At Copperdome they turn around and return to launch, landing at the Community Centre (orange line).   This flight would be scored as an out-and-return (OR) flight.

Scenario 2:  On the same flight, the same pilot, after returning from Copperdome, elects not to go out and land, but flies north once again, this time to Hurley launch (the blue line below).  At Hurley launch the pilot turns around and flies back to Pemberton, landing at the Community Centre (pink line).  This entire flight would be scored as an open-distance (OD) flight since there are multiple laps of the same terrain involved. 

The pilot could alternately choose to file an out-and-return (OR) flight for the first part of the flight (the black / red / orange lines), but not the second part of the flight (the blue and pink lines).