Hi, I am planning to go to Vienna from Salzburg, and when I have tried to add the journey on my Eurail Austria Pass there is "conditions apply" on the ticket.

It is shown in Eurail app that the train is EC (Eurocity?) so maybe the warning is relevant to this... but in OBB app it seems the train is also Railjet Express train, which is, to my knowledge, domestic train in Austria. Someone knows what causes the warning in this line?