In the United Kingdom, the Food Standards Agency has published criteria for the use of several terms in food labeling. The guidance, in general, restricts the use of natural foods that have "ingredients produced by nature, not the work of man or interfered with by man." Natural flavorings are explicitly defined by separate laws.
There are different standards for various types of food, such as dairy products.  It also gives standards for some food processing techniques, such as fermentation or pasteurization.  The standard explicitly rules out "foods derived from novel processes, GM or cloning."