Found the link. Text below is from the
SkyMiles Member Guide (my bolding):
On nonstop and direct or connecting flights with no change in flight number (whether or not the itinerary requires a change in aircraft), mileage credited will be calculated based upon the distance from origin to final destination, regardless of the number of stops
On connecting flights that require both a change of plane and flight number, mileage credited will be calculated based upon the distance from origin to destination for each segment of the trip. However, use of connecting itineraries in lieu of nonstop and/or direct flights for the accumulation of additional mileage is not permitted. Delta reserves the right to limit mileage credit for an itinerary to the number of connecting flights actually traveled or the maximum number of segments shown in Delta’s published schedule for a connection between any two cities, whichever is less