http://www.marinelink.com/news/uscg-interim-policy-re-marpol-annex-vi/uscg-interim-policy-re-marpol-annex-vi316609
USCG interim policy re MARPOL Annex VI
The U.S. Coast Guard issued a Policy Letter providing interim guidance regarding voluntary compliance with MARPOL Annex VI by U.S. vessels.