Originally Posted by
dfreeman02
When changing a ticket, the change fee is the highest fee for all *changed* fare components. So if you leave your S/T unchanged the Y/B (i.e. no) penalty applies. Even some res agents don't know this, but it's in the rules. (Though I'd recommend that if you're planning to do this, you read the fare rules carefully and make sure this clause is still there.)
You do have to worry about combinations though -- often the S/T is not combinable with the Y/B, and I can't find anywhere where these rules are written down.
This surprises me. If I understand your explanation, this implies that one could use cheap S/T fares that were intended to be roundtrip sale only for one-way trips, by (assuming they are combinable with Y) buying S/T outbound and Y for return, then refunding the unused Y, effectively having bought a one-way S/T. I don't think you can get away with this. The rule you've quoted discusses the size of the penalty/change fee - but are you also suggesting that refundability and advance-purchase remain unrestricted if one uses S outbound as originally ticketed, and then wants to change/refund the Y return?