You ARE permitted to sell:
Only accounts/items/services
You are NOT permitted to sell:
Hacks
Cheats
Scripts (aswell as Remote Exec)
Bypasses
Menus
Source code
Keystealers
Methods to sell keys
Remote Executives/Remove Executive Bypasser
Well that's only for the Day Z section, I don't think you can sell it though; you might want to PM Flengo to be sure though.