OK, I think I have the answer finally...
The AS flight from EWR/ORD (operated by AA) is only a valid flight in the system if you are continuing on AS ORD/ANC.
AS1680 EWR/ANC does not exist if you are not using AS to go to ANC.
So, they are selective code shares only valid if you are connecting on that carrier.
[This message has been edited by EWR-COflyer (edited 01-01-2002).]
[This message has been edited by EWR-COflyer (edited 01-01-2002).]