I don't see any DL codes on SK flights in the EU yet. There are DL fares that allow connecting flights on SK within EU, but they are not codeshared flights. DL TATL fares still require DL coded flights on DL/AF/KL/VS equipment on the TATL segment.

"AND IF THE FARE COMPONENT INCLUDES TRAVEL VIA EACH TRANSATLANTIC SECTOR THEN THAT TRAVEL MUST BE ON ONE OR MORE OF THE FOLLOWING ANY DL FLIGHT OPERATED BY DL ANY DL FLIGHT OPERATED BY AF ANY DL FLIGHT OPERATED BY KL ANY DL FLIGHT OPERATED BY VS. AND THE FARE COMPONENT MUST BE ON ONE OR MORE OF THE FOLLOWING ANY DL FLIGHT ANY AF FLIGHT ANY KL FLIGHT ANY VS FLIGHT OPERATED BY VS ANY AM FLIGHT ANY HA FLIGHT ANY WS FLIGHT ANY SK FLIGHT."