Each person who engages in the selling, delivering or transporting of nursery stock in this Commonwealth is required to attach on the outside of each package, box, bale, truckload or carload lot sold or delivered a tag or poster on which shall appear an exact printed copy of his valid certificate or license. The use of tags or posters bearing an invalid or altered certificate or license or the misuse of any valid certificate or license tag is prohibited.
3 P.S. § 258.15