Originally posted by z:
ATTENTION, it is point to point you will need a coupon for each segment.
The routing can be changed sometimes if it is the some mileage zone but the gates agent can refuse it because of taxes recalculation.
ZED is not necessarily point-to-point, this depends on the transporting carrier's requirements. Some airlines require pricing against each non-stop (point-to-point), others allow pricing against the O&D but require a coupon for each nonstop. Others allow pricing and ticketing against the O&D.

Z is correct that the decision to accept the ticket is up to the agent, but ZED rules generally provide that it be accepted as long as 1) the employing carrier has a ZED agreement with the new transporting carrier, 2) the fare paid is equal to or higher than the new applicable fare, and 3) the taxes collected on the ticket are the same for the new routing.

Zed Fares