[t-writescode]

Literally everyone I know calls it "Coke Zero" - in fact, the "Zero" pattern has spread to the various soda companies to reflect the particular style of zero sugar.

[KeplerBoy]

Sure, that's why it was a weird rebranding.

[pas]

They probably felt that it stopped being cool, it's now just a common name, so they went ahead and made it into something more legible.