Hi Greg, thank you so much for your very quick reply. > It's not necessary at this time. Good to know.I see. So in case I want it I'd have to add "contrib" and "non-free" in line 7 first.
Perhaps I'm a bit slow to understand, but what about lines 8, 11, 14 and 15 then? All these also contain just "main". Would they have to be altered as well?
Thanks a lot. Rosika