Bridal Registry

I think I have a different problem I would like to share with others. I have recently had a baby shower for our daughter and she was registered in two different stores. But unfortunately, a lot of people did not believe in "the registry," and purchased things that they liked. And, as I said, unfortunately, she did not receive anything that she really needed and now has to go shopping for the stuff on her own. I am now planning a wedding shower, and my question is, is there a tactful way of asking people to please shop from the registry, only? A poem, anything. Please help, anyone!!