End of Train lights on DPU locomotives

On a train that has rear-end DPU pushers, I believe the head (or tail, whichever way the unit is pointing) light is used as the "End of Train" light. Is this correct? If so, do these lights flash like a real EOT light, or are they just on solid? Thanks

At least on CSXT, the required rear marker is the headlight of the trailing unit set on "dim".

Here on the UP, DPU locomotives use their headlight as EOT lights as Jay Potter says.

The way the DPU is pushing can vary too, like the tail of the loco can be facing the last car and utilize the front headlight (at least this is how UP places the DPU), or the nose of the loco can be facing the last car and utilize the rear headilight .

Well, if the units use the head light as a rear light, it's just the ditch lights going forward, right?
http://www.railpictures.net/viewphoto.php?id=79797

This is actually an old rule that is being applied to the new way of doing things.
In the days before all this remote control technology came about, the rulebook said that instead of having the usual markers like cabooses always carried, rear end helpers would display a headlight on dim to the rear of the train. No ditch lights would be on. Just that headlight on dim whether it was actually the front or rear of the engine does not matter. Just so it is shining to the rear. It would'nt do much good if it were shining towards the car it was pushing on and ditch lights would really tick off any crews who were following closely behind the the train with the helper/dpu or overtaking it on an adjacent track.