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In order to express pinpoint location, latitude and longitude are not enough information, technically. Latitude and longitude needs information of Datum or geographic Datum. Datum is a basic factor of earth emulation, so same latitude and longitude shows slightly different location if you use different datum. In US, NAD27, NAD83, and WGS84 datum co-exists. In Japan, there are two datum, WGS84 datum became de facto standard because GPS system use it. Most code specifies which datum should be used. For example, NAC, GeoPo, LocaPoint, LP-Address, and most GEOCODEs specifies WGS84 datum. However, it is very important that which datum is the base of GEOCODE.