Check out this article written by a friend of mine who has been diagnosed with Celiac Disease. I went out for dinner with her recently to a local restaurant and they presented a gluten-free menu and then fried the food in a gluten contaminated fryer. When she kindly asked our server about it, the server was rude and annoyed with us.
Seriously, if you are a restaurant serving food and claim to have a gluten-free menu, do everyone a favor and educate your staff on what it is and what it means to cook gluten-free food. It really hurts your credibility and makes me question the quality of your food in general if you do not fully understand the disease. Furthermore, adding a disclaimer about how you cannot guarantee that the food will be completely gluten-free, proves that you are backing out of the commitment to fully cater to the people who suffer from this disease.