Can or need I register as doctoral student?
That depends on whether you are employed by the Freie Universität Berlin. If you are not an employee, registration as doctoral student in the Student Records and Registration Office within a period of four weeks after having been admitted as doctoral candidate is mandatory. Failing to register would render your admission void and you would have to re-apply for admission.
Employees of the Freie Universität Berlin are being asked to register, but are under no obligation to do so.