All cards issued out of the library provided for by City Code shall be deemed family cards and shall be deemed issued only to responsible persons over eighteen (18) years of age or to the heads of households. No card shall be issued to a minor child except in the event that a responsible adult agrees to accept full liability and responsibility for the actions of the child receiving the card. Any adult to whom the card is issued, or who signs a consent allowing a card to be issued to a minor child, shall be financially responsible for any loss or damage to any book or article removed from the library, or any damage done to any article within the library, or for any overdue books.