.ac (second level)

.ac is a second level domain for academic establishments, such as universities, in a number of countries, such as the United Kingdom (.ac.uk), Japan (.ac.jp), Austria (.ac.at), Belgium (.ac.be), South Africa (.ac.za), and many more. Many countries use .edu for the same purpose, for example .edu.au in Australia, .edu.my in Malaysia. Still other countries (examples include France and Switzerland), do not maintain a second level domain specifically for academic institutions. Rather, each institution will have its own second-level domain (such as sorbonne.fr for the Sorbonne, or tum.de for the Technical University of Munich).
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