If you're talking about the control wiring I'm going to say use class 1 and combine it with the other conductors. Seems the on/off switch and dimming control has line voltage on it as of course does the ballast. Control wiring connects to both within the same enclosures. I see no mention of CL2 or CL3 wiring being permitted which means that it is class 1.
To be sure you could give Universal tech support a call.
-Hal