Question regarding Miles one way cash return

Hello,

I was rethinking upcoming hols

Now thinking about using my miles to get 4 UC flights to mia (there is availability) and then paying cash to get 4 Y's back on the day flight from jfk 3 weeks later.

On reading the combo fares page its states that I cant use combo to get UC flights. but its a bit obtuse to my mind.

Does that mean I cant pay cash for upper back or does it mean I cant combine upper on miles and y cash. Its simply not clear to me!

So can I go upper miles out and return Y cash or not?

ta.

The reward part can be in Y, PE or UC, subject to availability

The paid fare sector can only be in Y or PE

Excellent. Just what I wanted to hear. THanks