1, The full form of IAO is Information Awareness Office. It’s used on Governmental ,Security & Defence in United States

The Information Awareness Office (IAO) was established by the Defense Advanced Research Projects Agency (DARPA) in January 2002 to bring together several DARPA projects focused on applying surveillance and information technology to track and monitor terrorists and other asymmetric threats to national security, by achieving Total Information Awareness (TIA). This would be achieved by creating enormous computer databases to gather and store the personal information of everyone in the United States, including personal e-mails, social networks, credit card records, phone calls, medical records, and numerous other sources, without any requirement for a search warrant.

2, The full form of IAO is International Accreditation Organization. It’s used on Associations & Organizations ,Educational Organizations in Worldwide

The IAO is an internationally recognized private education accrediting body. IAO oversees both online/distance learning colleges, universities and schools accreditation as well as traditional/campus based institues accreditation(accreditation is the act of granting credit or recognition (especially with respect to educational institution that maintains suitable standards).

3, The full form of IAO is International Astronomy Olympiad. It’s used on Associations & Organizations ,Conferences & Events in Worldwide

The International Astronomy Olympiad (IAO) is an internationally recognized annual astronomy scientific-educating event for high school students (14–18 years old), which includes an intellectual competition between these students. It is one of the International Science Olympiads.