Shipboard Energy Efficiency Management Plan Ships of 400 gross tons and above engaged in international voyages involving countries that have ratified the conventions, or ships flying the flag of those countries, are required to have an International Air Pollution Prevention Certificate (IAPP Certificate).The IAPP certificate will be issued following an initial survey carried out by the Flag Administration or by the Class (e.g. DNV, ClassNK) on behalf of the Flag Administration, confirming compliance with MARPOL Annex VI. For ships with the flag of an Administration that have not yet ratified Annex VI, a Certificate of Compliance with Annex VI issued by the Class.