Which organization’s rules are followed for the registration marks of aircraft in Hong Kong?

The correct answer is related to the International Civil Aviation Organization (ICAO), which is a specialized agency of the United Nations responsible for establishing global standards and regulations for civil aviation. In the context of Hong Kong, the registration marks of aircraft must comply with the standards set forth by the ICAO. These rules ensure that all aircraft operating internationally adhere to a consistent framework for identification, safety, and operational protocols.

ICAO's guidelines help maintain safety in air travel, including how aircraft registrations are formatted and displayed. This is particularly important in Hong Kong as it operates under the "One Country, Two Systems" principle, which allows it to follow international aviation norms while also complying with local laws and regulations. Thus, the registration marks used in Hong Kong aviation directly reference the protocols established by the ICAO, signifying compliance with international aviation standards and contributing to both safety and recognition globally.