Update: Bohemia Interactive has clarified that the classification, or absence of one, doesn't effect the digital version of DayZ, only the upcoming physical edition. It's still available on Steam in Australia.
Original story: DayZ has been refused an age rating by the notoriously strict Australian Classification Board. It's not unusual for games to not receive a rating in Australia, often leading to developers making changes to fit the draconian rules, but DayZ has been available in Australia for years. It entered Early Access in 2013 and finally launched last year.
The classification page (cheers, Reddit) shows the decision was made in June and was applied for by Five Star Games, an Australian distributor. The reason for it being refused classification, which essentially means it's banned, is that it depicts naughty things that might offend.
It apparently depicts or expresses matters of "sex, drug misuse or addiction, crime, cruelty, violence or revolting or abhorrent phenomena in such a way that they offend against the standards of morality, decency and propriety generally accepted by reasonable adults to the extent that they should not be classified."
DayZ was already rated, so it's not clear why it was refused classification when it's exactly the same game. We know DayZ is getting a physical edition this year, which is probably why distributor Five Star Games is involved. What doesn't make sense is why the rules would be different for digital and physical games.
So far, it's yet to affect Steam, as DayZ continues to be sold in Australia, but this may halt the physical launch. I've reached out to both Bohemia Interactive and Five Star Games for more details.