Actually that little "Contains:" message is by law required to be there if the product contians any of the top 8 allergens which wheat is one of them. Also having that label there is a good thing as well as the law. So any time you see that pass the product up it's not gluten free.
The eight foods identified by the law are:
- Fish (e.g., bass, flounder, cod)
- Crustacean shellfish (e.g. crab, lobster, shrimp)
- Tree nuts (e.g., almonds, walnuts, pecans)
If you want to go gluten free you need to avoid all sources of wheat, rye, barley, spelt, etc. Here's a list that shows which ones are ok and which are not http://www.csaceliac...rs_glossary.jsp