Location codes

GeoStan returns location codes that indicate the accuracy of the assigned geocode.

A Location Code of "E" indicates a location code is not available. This usually occurs when you have requested ZIP Code centroids of a high quality, and one is not available for that match. It can occur infrequently when GeoStan does not have a 5-digit centroid location. GeoStan can also return an E location code type when it cannot standardize an input address and there is no input ZIP Code. In this case, do not assume the ZIP Code returned with the non-standardized address is the correct ZIP Code because GeoStan did not standardize the address; therefore, GeoStan does not return geocoding or Census Block information.

Address location codes

Address location codes detail the known qualities about the geocode. An address location code has the following characters.


1^st character	Always an A indicating an address location.
2^nd character	May be one of the following:
	C	Interpolated address point location.
	G	Auxiliary file data location.
	I	Application infers the correct segment from the candidate records.
	P	Point-level data location.
	R	Location represents a ranged address.
	S	Location on a street range.
	X	Location on an intersection of two streets.
3^rd and 4^th characters	Digit indicating other qualities about the location.

The following table contains the address codes.


Code		Description
AGn		Indicates an auxiliary file for a geocode match where n is one of the following values:
	n=0	The geocode represents the center of a parcel or building.
	n=1	The geocode is an interpolated address along a segment.
	n=2	The geocode is an interpolated address along a segment, and the side of the street cannot be determined from the data provided in the auxiliary file record.
	n=3	The geocode is the midpoint of the street segment.
APnn		Indicates a point-level geocode match representing the center of a parcel or building, where nn is one of the following values:
	nn=00	User Dictionary centroid. Geocode returned by a User Dictionary.
	nn=02	Parcel centroid Indicates the center of an assessor’s parcel (tract or lot) polygon. When the center of an irregularly shaped parcel falls outside of its polygon, the centroid is manually repositioned to fall inside the polygon as closely as possible to the actual center.
	nn=04	Address point Represents field-collected GPS points with field-collected address data.
	nn=05	Structure point Indicates a location within a building footprint polygon that is associated with the matched address. Usually, residential addresses consist of a single building. For houses with outbuildings (detached garages, sheds, barns, etc.), the structure point will typically fall on the primary structure. Condominiums and duplexes have multiple, individual addresses and may have multiple structure points for each building. Multi-unit buildings are typically represented by a single structure point associated with the primary/base address, rather than discrete structure points for each unit. Shopping malls, industrial complexes, and academic or medical center campuses are commonly represented by a single structure point associated with the primary/base address for the entire complex. When multiple addresses are assigned to multiple buildings within one complex, multiple structure points may be represented within the same complex.
	nn=07	Manually placed Address points are manually placed to coincide with the midpoint of an assessor’s parcel’s street frontage at a distance from the center line.
	nn=08	Front door point Represents the designated primary entrance to a building. If a building has multiple entrances and there is no designated primary entrance or the primary entrance cannot readily be determined, the primary entrance is chosen based on proximity to the main access street and availability of parking.
	nn=09	Driveway offset point Represents a point located on the primary access road (most commonly a driveway) at a perpendicular distance of between 33-98 feet (10-30 meters) from the main roadway.
	nn=10	Street access point Represents the primary point of access from the street network. This address point type is located where the driveway or other access road intersects the main roadway.
	nn=21	Base parcel point The point data includes individual parcels that may be "stacked".These stacked parcels are individually identified by their unit or suite number, and GeoStan is able to match to this unit number and return the correct APN.If an input address is for a building or complex, without a unit number.The "base" parcel information returns and will not standardize to a unit number or return additional information such as an APN.
	nn=22	Backfill address point The precise parcel centroid is unknown. The address location assigned is based on two known parcel centroids.
	nn=23	Virtual address point The precise parcel centroid is unknown. The address location assigned is relative to a known parcel centroid and a street segment end point.
	nn=24	Interpolated address point The precise parcel centroid is unknown. The address location assigned is based on street segment end points.
AIn		The correct segment is inferred from the candidate records at match time.
ASn		House range address geocode. This is the most accurate street interpolated geocode available.
AIn, ASn, and ACnh share the same values for the 3rd character "n" as follows:
	n=0	Best location.
	n=1	Street side is unknown. The Census FIPS Block ID is assigned from the left side; however, there is no assigned offset and the point is placed directly on the street.
	n=2	Indicates one or both of the following: •The address is interpolated onto a TIGER segment that did not initially contain address ranges. •The original segment name changed to match the USPS spelling. This specifically refers to street type, predirectional, and postdirectional. Note: Only the second case is valid for non-TIGER data because segment range interpolation is only completed for TIGER data.
	n=3	Both 1 and 2.
	n=7	Placeholder. Used when starting and ending points of segments contain the same value and shape data is not available.
ACnh		Indicates a point-level geocode that is interpolated between 2 parcel centroids (points), a parcel centroid and a street segment endpoint, or 2 street segment endpoints.
The ACnh 4th character "h" values are as follows:
	h=0	Represents the interpolation between 2 points, both coming from User Dictionaries.
	h=1	Represents the interpolation between 2 points. The low boundary came from a User Dictionary and the high boundary, from a non-User Dictionary.
	h=2	Represents the interpolation between 1 point and 1 street segment end point, both coming from User Dictionaries.
	h=3	Represents the interpolation between 1 point (low boundary) and 1 street segment end point (high boundary). The low boundary came from a User Dictionary and the high boundary from a non-User Dictionary.
	h=4	Represents the interpolation between 2 points. The low boundary came from a non-User Dictionary and the high boundary from a User Dictionary.
	h=5	Represents the interpolation between 2 points, both coming from non-User Dictionaries.
	h=6	Represents the interpolation between 1 point (low boundary) and 1 street segment end point (high boundary). The low boundary came from a non-User Dictionary and the high boundary from a User Dictionary.
	h=7	Represents the interpolation between 1 point and 1 street segment end point and both came from non-User Dictionaries.
	h=8	Represents the interpolation between 1 street segment end point and 1 point, both coming from User Dictionaries.
	h=9	Represents the interpolation between 1 street segment end point (low boundary) and 1 point (high boundary). The low boundary came from a User Dictionary and the high boundary from a non-User Dictionary.
	h=A	Represents the interpolation between 2 street segment end points, both coming from User Dictionaries.
	h=B	Represents the interpolation between 2 street segment end points. The low boundary came from a User Dictionary and the high boundary from a non-User Dictionary.
	h=C	Represents the interpolation between 1 street segment end point (low boundary) and 1 point (high boundary). The low boundary came from a non-User Dictionary and the high boundary from a User Dictionary.
	h=D	Represents the interpolation between 1 street segment end point and 1 point, both coming from non-User Dictionary.
	h=E	Represents the interpolation between 2 street segment end points. The low boundary came from a non-User Dictionary and the high boundary from a User Dictionary.
	h=F	Represents the interpolation between 2 street segment end points, both coming from non-User Dictionaries.
ARn		Ranged address geocode, where "n" is one of the following:
	n=1	The geocode is placed along a single street segment, midway between the interpolated location of the first and second input house numbers in the range.
	n=2	The geocode is placed along a single street segment, midway between the interpolated location of the first and second input house numbers in the range, and the side of the street is unknown. The Census FIPS Block ID is assigned from the left side; however, there is no assigned offset and the point is placed directly on the street.
	n=4	The input range spans multiple USPS segments. The geocode is placed on the endpoint of the segment which corresponds to the first input house number, closest to the end nearest the second input house number.
	n=7	Placeholder. Used when the starting and ending points of the matched segment contain the same value and shape data is not available.
AXn		Intersection geocode, where "n" is one of the following:
	n=3	Standard single-point intersection computed from the center lines of street segments.
	n=8	Interpolated (divided-road) intersection geocode. Attempts to return a centroid for the intersection.

Street centroid location codes

Street centroid location codes indicate the Census ID accuracy and the position of the geocode on the returned street segment. A street centroid location code has the following characters.


1^st character	Always "C" indicating a location derived from a street segment.
2^nd character	Census ID accuracy based on the search area used to obtain matching Street Segment.
3^rd character	Location of geocode on the returned street segment.

The following table contains the values and descriptions for the location codes.


Character position	Code	Description
2^nd Character
	B	Block Group accuracy (most accurate). Based on input ZIP Code.
	T	Census Tract accuracy. Based on input ZIP Code.
	C	Unclassified Census accuracy. Normally accurate to at least the County level. Based on input ZIP Code.
	F	Unknown Census accuracy. Based on Finance area.
	P	Unknown Census accuracy. Based on input City.
3^rd Character
	C	Segment Centroid.
	L	Segment low-range end point.
	H	Segment high-range end point.

ZIP + 4 centroid location codes

ZIP + 4® centroid location codes indicate the quality of two location attributes: Census ID accuracy and positional accuracy. A ZIP + 4 centroid location code has the following characters.


1^st character	Always "Z" indicating a location derived from a ZIP centroid.
2^nd character	Census ID accuracy.
3^rd character	Location type.
4^th character	How the location and Census ID was defined. Provided for completeness, but may not be useful for most applications.

The following table contains the values and descriptions for the location codes.


Character position	Code	Description
2^nd Character
	B	Block Group accuracy (most accurate).
	T	Census Tract accuracy.
	C	Unclassified Census accuracy. Normally accurate to at least the County level.
3^rd Character
	5	Location of the Post Office that delivers mail to the address, a 5-digit ZIP Code centroid, or a location based upon locale (city). See the 4th character for a precise indication of locational accuracy.
	7	Location based upon a ZIP + 2 centroid. These locations can represent a multiple block area in urban locations, or a slightly larger area in rural settings.
	9	Location based upon a ZIP + 4 centroid. These are the most accurate centroids and normally place the location on the correct block face. For a small number of records, the location may be the middle of the entire street on which the ZIP + 4 falls. See the 4th character for a precise indication of locational accuracy.
4^th Character
	A	Address matched to a single segment. Location assigned in the middle of the matched street segment, offset to the proper side of the street.
	a	Address matched to a single segment, but the correct side of the street is unknown. Location assigned in the middle of the matched street segment, offset to the left side of the street, as address ranges increase.
	B	Address matched to multiple segments, all segments have the same Block Group. Location assigned to the middle of the matched street segment with the most house number ranges within this ZIP + 4. Location offset to the proper side of the street.
	b	Same as methodology B except the correct side of the street is unknown. Location assigned in the middle of the matched street segment, offset to the left side of the street, as address ranges increase.
	C	Address matched to multiple segments, with all segments having the same Census Tract. Returns the Block Group representing the most households in this ZIP + 4. Location assigned to t he middle of the matched street segment with the most house number ranges within this ZIP + 4. Location offset to the proper side of the street.
	c	Same as methodology C except the correct side of the street is unknown. Location assigned in the middle of the matched street segment, offset to the left side of the street, as address ranges increase.
	D	Address matched to multiple segments, with all segments having the same County. Returns the Block Group representing the most households in this ZIP + 4. Location assigned to the middle of the matched street segment with the most house number ranges within this ZIP + 4. Location offset to the proper side of the street.
	d	Same as methodology D except the correct side of the street is unknown. Location assigned in the middle of the matched street segment, offset to the left side of the street, as address ranges increase.
	E	Street name matched; no house ranges available. All matched segments have the same Block Group. Location placed on the segment closest to the center of the matched segments. In most cases, this is on the mid-point of the entire street.
	F	Street name matched; no house ranges available. All matched segments have the same Census Tract. Location placed on the segment closest to the center of the matched segments. In most cases, this is on the mid-point of the entire street.
	G	Street name matched (no house ranges available). All matched segments have the same County. Location placed on the segment closest to the center of the matched segments. In most cases, this is on the mid-point of the entire street.
	H	Same as methodology G, but some segments are not in the same County. Used for less than .05% of the centroids.
	I	Created ZIP + 2 cluster centroid as defined by methodologies A, a, B, and b. All centroids in this ZIP + 2 cluster have the same Block Group. Location assigned to the ZIP + 2 centroid.
	J	Created ZIP + 2 cluster centroid as defined by methodologies A, a, B, b, C, and c. All centroids in this ZIP + 2 cluster have the same Census Tract. Location assigned to the ZIP + 2 centroid.
	K	Created ZIP + 2 cluster centroid as defined by methodologies A, a, B, b, C, c, D, and d. Location assigned to the ZIP + 2 centroid.
	L	Created ZIP + 2 cluster centroid as defined by methodology E. All centroids in this ZIP + 2 cluster have the same Block Group. Location assigned to the ZIP + 2 centroid.
	M	Created ZIP+2 cluster centroid as defined by methodology E and F. All centroids in this ZIP + 2 cluster have the same Census Tract. Location assigned to the ZIP + 2 centroid.
	N	Created ZIP + 2 cluster centroid as defined by methodology E, F, G, and H. Location assigned to the ZIP + 2 centroid.
	O	ZIP Code is obsolete and currently not used by the USPS. Historic location assigned.
	V	Over 95% of addresses in this ZIP Code are in a single Census Tract. Location assigned to the ZIP Code centroid.
	W	Over 80% of addresses in this ZIP Code are in a single Census Tract. Reasonable Census Tract accuracy. Location assigned to the ZIP Code centroid.
	X	Less than 80% of addresses in this ZIP Code are in a single Census Tract. Census ID is uncertain. Location assigned to the ZIP Code centroid.
	Y	Rural or sparsely populated area. Census code is uncertain. Location based upon the USGS places file.
	Z	P.O. Box or General Delivery addresses. Census code is uncertain. Location based upon the Post Office location that delivers the mail to that address

Geographic centroid location codes

Geographic centroid location codes indicate the quality of two location attributes: the geographic location and area type


1^st character	Always "G" indicating a location derived from a geographic centroid.
2^nd character	Geographic area type.

The following table contains the values and descriptions for the location codes.


Character position	Code	Description
2nd Character
	M	Municipality (city).
	C	County.
	S	State.