Hello All,

I have done my masters from germany and now have a workpermit. On my visa in addition to work position as a project assistant in my company, it also states SELBSTSTÄNDIGE TÄTIGKEIT GESTATTET, which translates to self employment permitted.
My query is regarding, if i wish to be self employed then am i restricted to do work related to my field only i.e, architecture or i am allowed to do other work as well? 
If yes, then what paperwork do i need for it and where do i get it from?

Thanks for reply and help in advance.
Radhika