Under the name of Census Designated Place ( CDP, a defined settlement area for statistical purposes to German ), the United States Census Bureau recognized in every ten years held United States Census politically dependent areas, which can be distinguished from their surroundings due to demographic characteristics. CDPs get an official name, but are not Incorporated Places and therefore no authority.
The basis for the census in the United States have always been the municipalities (incorporated places ), so the County relative to the next lower, politically independent administrative unit. In many counties but do not cover the communities from the entire county area. Especially in the states in the Midwest and the Southwest, there are large areas that are not assigned to any community. Theoretically, can exist without a county municipalities.
To capture these areas but socio - demographically in the census, they are reported by the Census Bureau as a census -designated place. The boundaries of these CDPs are defined in cooperation with local authorities and are based on the actual settlement structures. It should by dividing the best CDPs those settlements are mapped, which are recognizable as such by the population distribution and location- like structures, the characteristics are not politically independent. In very sparsely populated areas the CDPs therefore are often significant. In keeping with the goal of mapping of urban structures can be adapted to count the classification depending on the residential development of counting. By 1990, there were minimum number of inhabitants as well as special exceptions for Indian reservations. At the 2000 census, these provisions were abolished.
ZIP Code Tabulation Areas
Since the validity of census -designated places in particularly sparsely populated areas is low, the Census Bureau evaluated according to the 2000 census, beginning with the data even after the postal codes designated as a ZIP code. Since the postal districts are not systematically Township, County and not even based on a few cases at national borders, the results of this evaluation are not directly comparable with other population data. In addition, ZIP codes often comparatively newly tailored, so that the assignment reflects only the current state.