Originally Posted by
ijgordon
Well I've never seen a fare rule that allows re-ticketing at historical (i.e., the original) fares when changing the first segment of an itinerary. That of course doesn't mean that such a fare doesn't exist. Certainly any agent would default to "you're changing the first segment so we have to rebook as a brand-new ticket". And beyond that, in my experience, some (many?) agents will also try to re-price the ticket when changing a continuing or return segment before travel has commenced, even though the fare rules say that you can keep the historical fares. You might have to instruct them to read the fare rules (which of course are NOT written in plain English!). Now, once the outbound portion is flown, the system will effectively default to using historical fares, so it's often "easier" to change the return after the outbound has been flown.
My general understanding was and is exactly as you describe it. Someone here corrected me once and pointed me to fare rules. I doubt I can search well enough to find it. It was not some odd ball fare, it was a mainstream fare that said, and I am paraphrasing, to not collect any extra fare if the same fare bucket was available.