Diet Coke
Diet Coke (called Coca-Cola Light in some countries) is a sugar-free and no-calorie soft drink produced and distributed by The Coca-Cola Company. It contains artificial sweeteners instead of sugar. Unveiled on July 8, 1982 and introduced in the United States on August 9, it was the first new brand since 1886 to use the Coca-Cola trademark. The product quickly overtook the company's existing diet cola, Tab, in sales.
Dr Pepper
As with Coca-Cola, the formula for Dr Pepper is a trade secret, and allegedly the recipe is kept as two halves in safe deposit boxes in two separate Dallas banks. A persistent rumor since the 1930s is that the drink contains prune juice, but the official Dr Pepper FAQ refutes this with "Dr Pepper is a unique blend of natural and artificial flavors; it does not contain prune juice." The origin of the rumor is unknown; some believe it was started by a deliveryman for a competitor trying to cast aspersions based on prune juice's laxative effects, but it may simply be because many people feel that Dr Pepper tastes similar to prune juice.