No, but it wouldn't matter if it's a manuf home or a site-built. Just follow directions. You have more options, however. You can choose something that may not radiate too much heat. But just make sure you use flashing and put shingles over it. But you probably know that.

I heard they can be tricky to install.

it's a great site for how-to's. There's even a skylight thread.

http://www.mobilehomerepair.com/forums/index.php?forum_id=8

thanks for the info

Yes.. we had a skylight installed in the livingroom 10 years ago. It's a fixed (non-opening) style - probably 2x4 ft vella brand. Had it installed professionally. He did a great job. Tip.. (we had this done too).. when they install it, instead of just cutting the well (hole) straight, have it angled so outward at each end so light spreads out more as it enters the room. I know someone else who had them build shafts extending upward on the roof, then putting the skylight on top of the shaft. it gave the appearance (from within) that the roof was way higher. (probably looked goofy from outside tho).