<P> RFC 7686 reserves the use of . onion for the self - authenticating names of Tor hidden services . These names can only be resolved by a Tor client because of the use of onion routing to protect the anonymity of users . </P> <P> In the late 1980s, InterNIC created the nato domain for use by NATO . NATO considered none of the then existing TLDs as adequately reflecting their status as an international organization . Soon after this addition, however, InterNIC also created the int TLD for the use by international organizations in general, and persuaded NATO to use the second level domain nato.int instead . The nato TLD, no longer used, was finally removed in July 1996 . </P> <P> Other historical TLDs are cs for Czechoslovakia (now using cz for Czech Republic and sk for Slovak Republic), dd for East Germany (using de after reunification of Germany), yu for SFR Yugoslavia (now using ba for Bosnia and Herzegovina, hr for Croatia, me for Montenegro, mk for Macedonia, rs for Serbia and si for Slovenia), and zr for Zaire (now cd for Democratic Republic of the Congo). In contrast to these, the TLD su has remained active despite the demise of the Soviet Union that it represents . ICANN's ccNSO is working on a policy for retirement of ccTLDs that have been removed from ISO - 3166 under the chairmanship of Nigel Roberts . </P> <P> Around late 2000, when ICANN discussed and finally introduced aero, biz, coop, info, museum, name, and pro TLDs, site owners argued that a similar TLD should be made available for adult and pornographic websites to settle the dispute of obscene content on the Internet and the responsibility of US service providers under the US Communications Decency Act of 1996 . Several options were proposed including xxx, sex and adult . The . xxx domain went live in 2011 . </P>

Dns domains that are not on the internet should use the top-level name