Originally Posted by
MSPeconomist
Exactly.
Moreover, some fares might not be combinable into RTs. A T fare outbound could require a T or other low fare class (nonrefundable) on the return, or if you want refundable (for whatever reason) in the return direction, the ticket could be forced into a full Y fare.
Yeah, that could be the case, but the more practical issue is that I don't think you can force Delta.com to mix refundable and nonrefundable anyway. You'd at least have to call an agent (or use a travel agent).