I can't tell from reading the FAQ and this thread what the answer is...
I have a flex M FP booking. I would like to change to a later flight that is Y1 M0.
The FP terms don't say anything about SDC, only:
* Flight credit booking changes are subject to availability.
* Only changes to flight departure time can be processed at the airport. Any changes to flight routing must be completed online or in exceptional circumstances by Air Canada Reservations.
Would I be able to make this change? (It's a few days away still so I can't test what happens after I check in.) I'm guessing it's no and I still require M to be positive? But I think SDC wouldn't have that requirement if it were possible?