What is the correct full form of IUCN?

Founded in 1948, the International Union for Conservation of Nature (IUCN) has become the worldwide authority on the status of the natural world and the measures needed to protect it. It is a membership organisation that is unique in that it includes both government and civil society organisations. IUCN is the global authority on the status of the natural world and the measures required to protect it, drawing on the experience, resources, and reach of its more than 1,400 Member organisations, as well as the input of some 15,000 experts.