The city centre business districts mostly lie within Dublin 1 and Dublin 2.
While the codes are mostly numerical only, Dublin 6W is an exception, defined when An Post attempted to create a new postal area in south Dublin. Residents of some areas, citing property devaluation, objected to the proposed amalgamation of their areas with those they considered to be less valuable.
Of all the post codes, Dublin 4 is by far the most famous, arousing various emotions in Dubliners and Irish country people alike.