Whenever any child is employed or permitted to labor at any gainful occupation permitted by the laws of this state, the employer of the child shall preserve on file the work permit of the child and shall keep posted in a conspicuous place about the premises where the child is employed a list of all children there at work by virtue of work permits. The form for all work permits shall be prepared by and shall contain such information concerning the identity of the child as may be prescribed by the labor and industrial division of the labor department.