Do you have to book these tickets on the "MU" airlines's website? Or, for that matter, do you have to book these airfares on the partner airlines website's? Lastly, if your Delta FF# doesn't appear after entering it on the reservation and the language barrier prevents you from doing it at "check in", could you just send the boarding passes to Delta for "MQD" credit?
Thanks in advance. I've been asking this question for over 2 years with no straight answer.