UK perspective here:
As per strict etiquette:
Including registry information with the invitation is not done.
Asking for charitable donations instead of gifts is a bit dicey, but is (In my opinion) acceptable.
Putting the request in the invitation is the same as putting registry information in.
That said, in my own personal opinion, there is nothing wrong with requesting donations instead of gifts (and please remember that here the charity claims back the tax if the Giftaid scheme is used), and putting such a request in with the general information sent with the invitation is fine (although a registry wouldn't be)
Mind you, I have no problem with "No gifts" either.