Section 16. Every employer, except employers of persons engaged in domestic service in the employer’s home, subject to a minimum fair wage order shall keep a copy of such order posted in a conspicuous place in every room in which persons are employed. Employers shall be furnished copies of orders on request without charge. The commissioner may require each employer in any occupation subject to this chapter to post rules which apply to such employer’s employees, in such reasonable way or ways and for such length of time as he may direct.