How do you use a parking disc in a blue zone?

What does this rule or driving tip mean?A blue zone limits how long you may park. The signs show the applicable times and maximum duration; the parking disc makes your arrival time visible.How to apply this safelyRead the zone sign in full when entering the area.Place the disc clearly visible behind the windshield.Do not move the disc unless you have actually moved and parked the vehicle again.Driving lesson and test tipThink of parking as a complete task: choose a space, check the rules, park the vehicle safely, and leave it correctly.Remember: Set the parking disc to the next full or half-hour mark and place it visibly on display.View the source: RVV 1990, article 25.