The Paris Conference on Passports & Customs Formalities and Through Tickets was a conference organised by the League of Nations in 1920 which agreed, for the first time, on a set of standards for all passports issued by members of the League. Prior to that time, there were no internationally agreed standards for passports because they were not generally required for travel until World War I . With the establishment of the International Civil Aviation Organization (ICAO) in 1947 (which had 188 contracting states) the responsibility for setting passport standards passed to that authority.