These do not require consideration by the Council, since standards for them are provided in these books, and enforced under the provisions of the federal Food and Drugs Act, except that they may be mentioned for information. Consideration by the Council becomes necessary if a U. S. P. or N. F. product is offered for sale under a name other than that, or the synonyms, under which the product is described in one of these books of standards, or if the proprietors or their agents advance claims that the product possesses therapeutic properties other than those commonly accredited to it. MODIFICATIONS OF U. S. P. AND N. F. PRODUCTS.--A pharmacopeial or National Formulary product which is marketed under the official title or synonym, but with well-founded claims that its purity, permanence, palatability or other physical properties excel the official standard, may, if no extraordinary therapeutic properties are asserted, be considered as an official article and held not to be within the scope of New and Nonofficial Remedies. When such products are marketed under the claim that they possess therapeutic properties other than those commonly accredited to the U. S. P. or N. F. products of which they are modifications, they shall be subject to the consideration of the Council. SPECIFICALLY EXEMPTED PREPARATIONS.--Foods, in general, unless marketed with the claim that they possess therapeutic properties shall not, at the present time, be considered by the Council. Mechanical appliances, at the present time, shall not be considered by the Council. Mineral waters (natural), at the present time, shall not be considered by the Council. With these exceptions, products which in the judgment of the Council are manufactured and marketed in conformity to the principles underlying the rules of the Council may be accepted for N. N. R. Products which are manufactured and marketed in a manner which does not conform to the principles underlying the rules of the Council shall not be accepted for N. N. R. The burden of proof in establishing claims for therapeutic properties of products considered by the Council shall lie with the proprietor or, when a foreign made product, with the agent who markets the product in the United States. To avoid confusion with nonofficial substances marketed under similar names, the Council recommends that official substances be prescribed by their official titles, followed by the abbreviation “U. S. P.” or “N. F.”; thus: Tinctura Nucis Vomicae, U. S. P.; Elixir Gentianae, N. F.