Site level match code associated with the restricted geocodes for the Place.
Site level geocodes are estimated through a proprietary interpolation algorithm using known street segment ranges with the address numbers. If a street segment is 100 to 200 Main Street, as an example, and there are 5 known addresses on one side of that street, then the geocodes are evenly spaced out in fifths along that street segment. Address parity is then used to see which side of the street an address falls. If the address falls on the left side of the street, then that point is shifted to the left; if it is on the right side, then the point is shifted to the right of the street to get the geocode for that address.
ZIP4 Centroid geocodes are plotted at the geographic center of the 9-digit ZIP4 area, which is about the size of a city block.
ZIP+2 Centroid geocodes are plotted at the geographic center of the 7-digit ZIP+2 area, which is usually in the general area of the neighborhood or business district.
ZIP Centroid geocodes are very simple and the least accurate that Infogroup offers. The latitude and longitude coordinates are simply plotted at the geographic center of the 5-digit ZIP code. CIP-centroid geocodes are used when very little address information is available and a more accurate geocode is unable to be assigned.