I was on the Fantasy mid-February, and one of the drink stations on deck 11 had Coke Zero. In the MDR embarkation lunch, I asked my server for coke zero, and he replied that I could only get diet coke. When I made a yuck face, lol, he said wait a minute he'd see what he could do. He came back with a can of coke zero, no charge...said he'd asked the head waiter and it was okay. He also said to ask my head waiter that night in the MDR...so I told this to my waiter at dinner, and he talked to the head waiter...and they agreed that since coke zero was available from the fountains for free, there shouldn't be a problem getting it for me at dinner. So I was presented with a can of coke zero at every dinner without asking, it just took longer as he had to get it from the bar along with the alcohol. I checked my bill at the end, and there was never a charge for any of the cokes. Thank god, cause diet coke is icky!