No junk dealer shall purchase or receive in pledge or on deposit for any purpose, in the course of his business, any goods, article or thing of value whatever from any minor within the city, or any goods, articles or thing of value, the ownership of which is in, or which is claimed by, any minor, or which may be in the possession or under the control of a minor, unless such minor's parents or guardian shall state in writing that such transaction took place with such parent's or guardian's full knowledge and consent, and it shall be the duty of such dealer to preserve and keep on file such written statement for the purpose of subsequent reference thereto.
('68 Code, § 16-5) Penalty, see § 10.99