Originally Posted by
rmratc
Because the PDC transmits basically a copy of the flight strip. We see the filed route and any preferential departure or arrival routes in between the +'s. The filed routing is on there to know where the change ties back into the original routing as well.
The information that is sent on the PDC's will eventually be standardized between facilities so they should all look they same and the information should be in the same order.
As you may or may not be aware, although there is a reason on the ATC end as to why the filed is on the release, the amount of ASAP-NASA reports about clearances would seem to dictate change.
Standardization will help also between the facilities.