In Germany I've also never been told to take a PNV, and I haven't seen them sold - just folic acid for the first 3 months. I figure if I'm eating a balanced diet it'll be fine.
I don't know if this counts as a rule, but I think I read that only 30% of US hospitals even allow patients to attempt a VBAC. Here it's the norm unless there's a medical reason for a RCS. However, at least in the hospital I deliver at, they do not allow VBA2+Cs. If you've had 2 c/s, then that's it.
Otherwise the rules seem pretty much the same to me - avoid deli meat, too much caffeine, alcohol (although my MW said a sip of champagne on NYE is fine), etc.