National coats of arms, national flags and municipal coats of arms are examples of official designations. You are not allowed to use them as trademarks without permission.
Official designations like national coats of arms, national flags, municipal coats of arms and state control designations cannot be registered as a trademark. You need permission from the appropriate authority to use them.
Read more about official designations in the Act on Protection for Coats of Arms and Certain Other Official Signs (1970:498).