As Unturned 4.0 will now be called Unturned II, it might get confused with the original Unturned 2.0. Here is how I think it should be called:
Unturned 1.0/Antique should be renamed to Unturned 1.1
Unturned 2.0/Classic should be renamed to Unturned 1.2
Unturned 3.0 should be renamed to Unturned 1.3
and Unturned 4.0/Unturned II should be renamed to Unturned 2.1
Thats how I think it would be. The version after 2.1 should be called Unturned 2.2 and then the version after that would be renamed to 2.3, etc. etc.