Nachum Lamm posts: The most important part of the ingredients is "natural flavors," which is undefined.
It doesn’t much matter if people knew Coke’s formula: There is one legal importer of coca leaves in the United States. It extracts the cocaine and sends it all to a single pharmaceutical company, sole producer of medicinal cocaine in this country. It sends all the de-cocained leaves to Coca-Cola for flavoring. There’s no other way to legally get cocaine leaves, and they won’t sell them to anyone but Coca-Cola. (The source of the other half of the name, Kola nuts, are a source of caffeine and are replaced with artificial equivalents in almost all colas today.)
Of course, well over 90% (over 95%, probably) of any soft drink is water, carbon dioxide, and sweetener, all of which are added at bottling plants, not the source.