Diet Coke
Diet Coke does not use a modified form of the Coca-Cola recipe, but instead an entirely different formula. The controversial New Coke, introduced in 1985, used a version of the Diet Coke recipe that contained high fructose corn syrup and had a slightly different balance of ingredients. In 2004, Coca-Cola introduced Coca-Cola C2, which it claims tastes much closer to Coca-Cola but contains half the carbohydrates. In 2005, the company introduced Coca-Cola Zero (replaced by "Coca-Cola Zero Sugar" in 2017), a sugar-free variation of regular Coca-Cola.
Diet drink
In countries outside of the United States, United Kingdom and Canada, the term "light" is often used instead of "diet"; sometimes, even in countries that do not speak English, the word "light" in English is used (e.g., "Coca-Cola Light" in Spain). The formulation of these is slightly different than the "diet"-named versions and thus the taste is slightly different.