Certification Region
- 5 - US 50 states.
- A - US federal, including altitude, may include Canada and/or Mexico.
- B - US California, includes US green states.
- C - Canada.
- D - China.
- E - European Community (Austria, Belgium, Denmark, Finland, France, Germany, Greece, Ireland, Italy, Luxembourg, Netherlands, Portugal, Spain, Sweden, United Kingdom).
- F - Extended European Community (E plus Croatia, Czech Republic, Estonia, Hungary, Norway, Poland, Romania, Russian Federation, Slovakia, Slovenia, Switzerland, Yugoslavia).
- G - Gulf Cooperative Council (Bahrain, Kuwait, Oman, Qatar, Saudi Arabia, United Arab Emirates).
- H - Hong Kong.
- J - Japan.
- K - Korea.
- L - Malaysia.
- M - Mexico.
- N - New Zealand.
- P - Australia.
- Q - South America (Brazil).
- S - Singapore.
- T - Taiwan.
- U - South America (unleaded fuel).
- V - Vietnam
- X - Rest Of World (ROW).
- Y - Military.
- Z - Israel.