Air Services Agreements (ASAs) are formal contracts between countries – Memorandums of Understanding (Memorandum of Understanding) and formal diplomatic notes. It is not mandatory to have an ASA for the operation of international services, but cases where contract-free services exist are rare. The third and fourth freedoms allow a fundamental international service between two countries. 146 Even if reciprocal rights are granted under the third and fourth freedoms, air services agreements (e.g. B Bermuda conventions) can still restrict many aspects of traffic, such as aircraft capacity, frequency of flights, airlines and airports to be served. :146-147 The third freedom is the right to transport passengers or goods from their own country to another. :31 The right to transport passengers or cargo from another country to one`s own country is the fourth freedom. :31 Third and fourth freedoms are almost always granted simultaneously in bilateral agreements between countries. The fifth freedom allows an airline to transport revenue traffic between the country as part of the services that connect the airline`s country.
 It is the right to transport passengers from one`s own country to a second country and from that country to a third country (and so on). An example of a fifth right of traffic is an Emirates flight in 2004 from Dubai to Brisbane, Australia and further afield to Auckland, New Zealand, where tickets can be sold in any area. 34 The first two freedoms concern the passage of commercial aircraft into foreign airspace and airports, while the other freedoms concern the international transport of people, mail and cargo. The first to the fifth freedoms are officially listed by international treaties, especially the Chicago Convention. Several other freedoms have been added and, although most are not officially recognized in international treaties of general application, they have been agreed by a number of countries. The freedoms cited in lower numbers are relatively universal, while the higher numbers are rarer and more controversial. Open-air liberal agreements are often the least restrictive form of air agreements and can encompass many, if not all, freedoms. They are relatively rare, but recent single air transport markets in the European Union (European Aviation Area) and between Australia and New Zealand are examples.