IFR clearance
PDC

Why does ATC send the filed and the actual route clearance on a PDC?
Without a PDC, ATC does not muddy the water with their readback of both filed and actual routing. Why are they doing it with PDC's?

I have a release, so I know what the filed route is. No need to add confusion with the clearance.

And to make matters worse, the format and display order between filed and cleared can vary from airport to airport!

I agree that this needs to be standardized.

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.

The standardization that will be coming is just the order the PDC is presented. Basically following the read clearance, SID, Altitude, frequency, and then other information. From my experience both on receiving pdc's and issuing them, the airlines don't do enough training on how to properly read them.

The questions that seem to come up the most at RDU is where does the route tie back in. For ex: filed route was tyi j79 JFK, and strip posts a change to +tyi j79 sby+. Most don't realize or get the chart out to verify that sby is on j79 and there was no change to what was filed. The plus routing is really just for computer processing/acceptance.