Originally Posted by
Kiwi Flyer
It is not a oneworld rule per se, but rather IATA rule.
An x for transit is treated differently to an o for stopover. A ticketed stopover can be utilised for a transit (under 24 hours) but a ticketed transit can never be utilised for a stopover (over 24 hours).
It isn't a reroute fee but a reticketing fee. Some changes require reticketing while others do not.
AA has never charged me for re-issuing the ticket. In my experience, AA tends to re-issue the ticket even for simple date and time changes. AA has only charged me the $125 when the ticketed points have changed (including switching the order of two airports).