NIAG meaning in General ?

Answer: What is National Information Assurance Glossary mean?

Committee on National Security Systems Instruction No. 4009, National Information Assurance Glossary, published by the United States federal government, is an unclassified glossary of Information security terms intended to provide a common vocabulary for discussing Information Assurance concepts.

The glossary was previously published as the National Information Systems Security Glossary (NSTISSI No. 4009) by the National Security Telecommunications and Information Systems Security Committee (NSTISSC). Under Executive Order (E.O.) 13231 of October 16, 2001, Critical Infrastructure Protection in the Information Age, the President George W. Bush redesignated the National Security Telecommunications and Information Systems Security Committee (NSTISSC) as the Committee on National Security Systems (CNSS).

The most recent version was revised April 26, 2010.

reference

Full Form	Category
Nuclear Interdiction Action Group	Academic & Science
Niagara Corporation	Business
National Information Assurance Glossary	General
NATO Industrial Advisory Group	Governmental