the point is not regarding DL acceptiing a zed--it's a zed tkt purchased per DL rules/agreement and if another carrier will or will not accept the DL issued zed (or whichever airline has whatever rules) I'm not crazy enough to buy a zed for AF CDG to ZRH and find out I can't use is for CDG to CAI or CDG to ARN (even if they are priced in the same zone--ZED is for zone pricing not ravel anywhere within that mileage zone) Thta's my take on the system as our rules read. Maybe it differs with another airline.