To the best of my knowledge the actual name is still a work-in-progress idea, the screen shots posted reflect actually "1.50 beta 1", as far as signifying anything 'unofficial', Witten has the support of both zilmar and myself in doing what he is, so in that sense it's official, but since neither zilmar or myself really have anything to do with the actual release, some might view it as "unofficial"... these thing should all be considered in coming up with a naming convention i suppose, these might help
° Project64 1.50 beta 1
° Project64 1.4.1
° Project64 1.40a
° Project64 1.41
Using letters like 1.40a is something I use to do in a few projects, however my tastes have changed recently and I personally prefer the 1.4.1 semantic, but i still think it's a valid option. I don't know how cool "Cheats Edition", or "Witten Edition" ... but appending "Unofficial" to it I could see, but it's not up to me really..