<P> ICAO is also responsible for issuing alphanumeric aircraft type codes containing two to four characters . These codes provide the identification that is typically used in flight plans . The Boeing 747 would use B741, B742, B743, etc., depending on the particular variant . </P> <P> ICAO has a headquarters, seven regional offices, and one regional sub-office: </P> <Ul> <Li> Headquarters--Montreal, Quebec, Canada </Li> <Li> Asia and Pacific (APAC)--Bangkok, Thailand; Sub-office--Beijing, China </Li> <Li> Eastern and Southern African (ESAF)--Nairobi, Kenya </Li> <Li> Europe and North Atlantic (EUR / NAT)--Paris, France </Li> <Li> Middle East (MID)--Cairo, Egypt </Li> <Li> North American, Central American and Caribbean (NACC)--Mexico City, Mexico </Li> <Li> South American (SAM)--Lima, Peru </Li> <Li> Western and Central African (WACAF)--Dakar, Senegal </Li> </Ul> <Li> Headquarters--Montreal, Quebec, Canada </Li>

Which of the following is not a foreign policy principle which singapore adopts