Reuters bangs the DY drum some more:
http://www.reuters.com/article/2013/...98S0HR20130930
Just checked, SK/TG/LH for example don't accept anything in DY ticket stock. So DY would have to all up LH/SK/TG to book an actual ticket on the operating carriers stock. DY is very clear to agents:
NORWEGIAN DOES NOT HAVE INTERLINE AGREEMENT WITH ANY OTHER AIRLINES