.dd part of the Federal Republic of Germany, which had already been assigned the ccTLD .de. The ISO 3166-1 code "DD" was withdrawn in 1990. .dd .dd was the assigned country code top-level domain (ccTLD) for the German Democratic Republic (East Germany). It was chosen based on the ISO 3166-1 alpha-2 code for the German Democratic Republic, the letters coming from the German name of the country: '. In accordance with IANA policy, .dd was therefore available to be assigned as the country code top-level domain (ccTLD) for East Germany. However, this was never done, and so .dd was never added
Single-letter second-level domain .pn .pr .pw .ro .sh .st .tc .tl .tt .to .tv .ua .ws .vc .vg .vn and .vu. Single-character non-ASCII second-level domains also exist (as seen below), also known as Internationalized domain names (IDN), these domains are actually registered as their Punycode translations (which are more than a single character) for DNS purposes. In 2012, the Public Interest Registry (PIR) initiated "Project94", in which 94 one- and two-letter domains in the top-level domain "org", that had been traditionally reserved, are awarded to qualifying organizations. Two-letter second-level domain names under the new generic top-level domains are viewed as a potential source