.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: Deutsche Demokratische Republik. 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 to the root nameservers. Its only use was internally at the universities of Jena and Dresden.
With the reunification of Germany, East Germany became 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 The ISO 3166-1 code "DD" was withdrawn in 1990.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, or other variants may refer to:
<dd></dd>
, an HTML element for specifying definition dataThe D Sixth Avenue Express is a rapid transit service in the B Division of the New York City Subway. Its route emblem, or "bullet", is colored bright orange since it uses the IND Sixth Avenue Line in Manhattan. The D operates at all times between 205th Street in Norwood, Bronx, and Stillwell Avenue in Coney Island, Brooklyn via Grand Concourse in the Bronx, Central Park West / Sixth Avenue in Manhattan, the north side of the Manhattan Bridge, and Fourth Avenue / West End in Brooklyn. The D runs express in Manhattan and makes all stops on the BMT West End Line in Brooklyn at all times. It makes all stops in the Bronx except when it runs express in the peak direction during rush hours. The D runs express on Fourth Avenue at all times except nights when it serves all stops.
D service began on December 15, 1940 when the IND Sixth Avenue Line opened. It ran from 205th Street, the Bronx to World Trade Center (at that time called Hudson Terminal) on the IND Eighth Avenue Line, switching between the IND Sixth Avenue to the Eighth Avenue Lines just south of West Fourth Street – Washington Square.