Every egg handler or dealer that pays assessments on a monthly basis, in lieu of seals, shall have their permanent dealer's number imprinted upon all containers that require assessment fees as provided by the "Washington Wholesome Eggs and Egg Products Act." The permanent egg handler or dealer's number shall appear on the outside of the container closure, the characters shall be not less than 1/8 inch in height. The numbers shall be preceded by the letters WA- or 53-, which designates the state of Washington.