I'm pretty sure that's how it's supposed to work (U designating taper), however, it's not tough to check.
There's a couple methods:
One is to get a caliper (I've used an adjustable wrench in a pinch) and set it to the tip, then slide it upwards. In a parallel tip shaft, you should be able to get at least 5" of travel before the shaft begins to get bigger.
The other is to drill a hole in a piece of wood the size of the shaft tip, then see how far you can pass the shaft through. Again, 5"+ of travel would indicate parallel.
The other method (possibly) is to check with the True Temper site to see what the stepping pattern is on the two shafts, then measure yours.
DG Taper (
http://www.truetemper.com/golf/shado...LD%20TAPER.pdf
DG Parallel (
http://www.truetemper.com/golf/shado...20PARALLEL.pdf)
That's probably the best idea, there.