Re-registration

• What is re-registration and why do I have to re-register?
• How do I re-register?
• When do I need to re-register?
• How much does re-registration cost?
• What happens if I don't re-register?
• What does the message “Wichtige Information: Die Rückmeldeaufforderung wird erst nach Erfüllung bestimmter Voraussetzungen möglich!” mean?
• I am almost finished with my studies. Do I still need to re-register?
• Why have I not received a re-registration request?
• I’ve already made the payment, but I’m still not being re-registered. What's going on?