This is all very well, but not when your postal vote arrives the morning of the election!
I was please to note that one of the LibDem leaflets actually (nearly) explained this. I say nearly because they did not make it clear you could chose either of the two for European only reminded students they could vote in the locals at home.
This is something of which I have been aware for a while but I never had it officially confirmed until I actually emailed someone at the electoral comission. It did not appear to be in their FAQs which struck me as stupid.