LBJ, the chart you and manacit posted is very clear. here is what I found on the DL website that led to my question. Not sure where you found the chart, thanks to both of you for posting the chart.


Virgin Atlantic-marketed flights in the following fare classes are eligible for accrual based on the percentages in the table below, multiplied by the flight distance (as determined in Delta or the partner carrier’s sole discretion)1.



MILEAGE EARN ON/AFTER JAN. 1, 2018Class Exclusions: If a class is not listed, no miles are earned.

Other Exclusions: Accrual is only eligible for flights operated by Virgin Atlantic, Delta, Delta ShuttleŽ or Delta ConnectionŽ

(1) Partner-marketed flights will earn miles based on a percentage of distance flown* as determined by the fare class paid. Unless otherwise noted, mileage credit is only applicable to Delta partner flights that are marketed and operated by that partner or Delta.
(2) Medallion Qualification Miles (MQMs) are used as a counter to determine SkyMiles Medallion status. Flights and itineraries eligible for MQMs will earn a minimum of 500 MQMs per segment.
(3) Medallion Qualification Dollars (MQDs) apply to Medallion qualification. Flights marketed by the partner will earn MQDs based on a percentage of distance flown* as determined by the fare class paid.
(4) Medallion Mileage Bonus is based on Base Miles earned: Diamond - 120%; Platinum - 80%; Gold - 60%; Silver - 40%

*For purposes of calculating mileage credit and MQDs, "distance flown" means the calculated distance between origin and destination, as determined by Delta in its sole discretion, regardless of the actual distance traveled on any individual flight.

In cases where these changes result in a loss of redeemable miles for tickets booked prior to 10/26/17 and flown after 1/1/18, customers may request mileage credit through the Mileage Request Form after all travel on a given ticket is completed.