How do I implement freelance work, project roles and bogus self-employment risk management in practice?

In Germany, freelance roles, service-oriented projects and traditional employment should be strictly categorised separately. Describe project roles with information on duration, location, service type and degree of supervision. Flag cases to employers where a freelance role is described as heavily integrated. Note: not every long-term project role is automatically problematic. (Evidence: Nachweisgesetz Gesetze im Internet, DRV Scheinselbststaendigkeit)