Turf grass complying with these regulations may be issued a Certified label. The participant shall attach the Certified label to the invoice or delivery ticket accompanying each load or shipment. A participant may not provide a label after the turf grass has been delivered. A participant may not claim turf grass as Certified unless accompanied by a Certified label. Certified turf grass labels will be valid for the following dates: May 1 through October 31; and November 1 through April 30.