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 Coke Lime
Diet Coke with Lime was discontinued in the UK as was Diet Coke with Lemon in early 2007, having been renamed Diet Coke with Citrus Zest in 2007, which is mixture of lime and lemon taste. In 2009, "Coca-Cola Freestyle" machines began carrying "Coca-Cola with Lime", along with its Diet counterpart. The regular version has since been discontinued, but the Diet version continued with steady sales until 2018. The diet version is now discontinued and replaced with Diet Coke Ginger Lime.