Engine Identification Engine Certification Label An engine certification label is attached to the engine rocker cover. This label certifies the engine conforms to federal and state emissions regulations for its application. It gives the operating conditions under which certification was made. The following illustration is an example of an engine certification label. Figure 7. Engine Certification Label 20 All information subject to change without notice. Copyright © 2019 DETROIT DIESEL CORPORATION DDC-SVC-MAN-0209