Key:border_type
 border_type
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| Description |
|---|
Distinguishes a boundary by its formal designation in the real world, or distinguishes between a country's different maritime limits. 
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| Group: boundaries |
| Used on these elements |
    |
| Documented values: 2 |
| See also |
Status: approved
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| Tools for this tag |
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This key distinguishes a boundary by its formal designation in the real world (sometimes known as the generic in toponymy). Additionally, four values have been approved for use with boundary=maritime, to distinguish between the concentric limits of a country's international border at sea.
Administrative boundaries
This key is especially useful in countries where two peer boundaries can have different real-world designations, despite sharing a common parent and admin_level=*. It was originally associated with several large boundary imports. Since each import focused on a one-to-one translation from the original source's attributes, the values are not harmonized across international borders. A given value can refer to multiple very different kinds of borders.
In general, the values of this key follow feature naming conventions: lowercase, snake_case, English words, in British English spelling when possible. The value is what the local administration would use in English. There is no attempt to "translate" these terms to analogous terms in the United Kingdom's official administrative hierarchy. Note that English often borrows jurisdictional terms from other languages, especially European languages. For example, "arrondissement" is the usual English word for the French arrondissement. Contrary to the prevailing usage elsewhere, the communities in Catalonia, Lithuania, and Portugal have standardized on values in Catalan, Lithuanian, and Portuguese, respectively, even when there are obvious English translations.
Additionally, border_type=suburb and border_type=suburban are commonplace but appear to be redundant to place=suburb on associated place nodes.
Maritime boundaries
See page of boundary=maritime for usage of the following values:
- border_type=baseline - Baseline
- border_type=contiguous - Contiguous Zone at 24 nautical miles (44 km; 28 mi)
- border_type=eez - Exclusive Economic Zone (EEZ)
- border_type=territorial - used with boundary=administrative for national borders at sea.
Regional variations
China
An import in China used the values:
- province
- prefecture
- county
- township
Lithuania
Used admin level values in Lithuania:
- apskritis (county) admin_level=4
- rajonas (district) admin_level=5
- seniūnija (eldership) admin_level=6
- gyvenvietė (locality) admin_level=8
- seniūnaitija (sub-eldership) or seniūnija in cities admin_level=10
Portugal
Admin level values for Portugal (as approved in this proposal):
United States
A 2008 import of a 2001 USGS dataset of county boundaries used the tag border_type=county, while a 2009 import of places set border_type=* according to the NAME and NAMELSAD fields in TIGER 2007. [1] (Note that some of the following tags are no longer preferred in these situations.)
| TIGER 2007 | 2009 import |
|---|---|
NAMELSAD ends with "unified government" |
border_type=city place=city |
NAMELSAD ends with "CDP" |
place=locality |
NAMELSAD ends with "AFB" |
landuse=military military=airfield |
NAMELSAD starts with NAME |
border_type=NAMELSAD place=NAMELSAD |
CLASSFP is "M2" |
landuse=military |
Subsequently, the U.S. community began to apply border_type=* even to boundaries that had not been imported. Currently known values are:
- territorial (including Commonwealths) corresponds to admin_level=4, though when it is on maritime boundaries (United States Minor Outlying Islands), the corresponding tag is admin_level=2
- state (or district for District of Columbia) corresponds to admin_level=4
- county/parish/borough (in states), municipality (in territories) correspond to admin_level=6
- township usually corresponds to admin_level=7, though there are exceptions
- city, town usually correspond to admin_level=8, though there are exceptions
- village corresponds to admin_level=8 or 9, depending on the state (or territory: villages are admin_level=6 in Guam and CNMI / Commonwealth of Northern Mariana Islands)
- unincorporated_place corresponds to admin_level=8 emerging (2024-Q1) in New England; see our community forum.
- community_improvement_district corresponds to admin_level=8 in South Dakota.[1][2]
These should give the legal status of the boundary. This may be different from the place=* value or the admin_level=*. The values "territorial" and "municipality" (specific to territories, not states) have been added after the above-noted import. "Municipality" is included on the same line as county to indicate that in territories, Municipality is assigned admin_level=6, the same as county, regardless of its name ("island group," "district," "municipio," "village," "unorganized atoll," et cetera).
Census divisions
border_type=* is used with boundary=statistical for the following census divisions:
| Tag | Meaning |
|---|---|
| border_type=census_designated_place | Census-Designated Place |
| border_type=census_county_division | Census County Division, also known as "Unorganized Territory" in some states. |
Software support
border_type=* is generally not consumed by map data providers.
border_type=* is not used by Nominatim to determine a boundary's named type. Nominatim only uses admin_level=* and place=* for classifying administrative boundaries.
border_type=* is used by the Wikidata quality assurance checker for United States boundaries.
Alternatives
admin_title=* is identical to this key but far less common and limited to classifying administrative boundaries, without the classifications for maritime boundaries.
designation=* is used on a variety of feature types with a purpose akin to usage of border_type=* on boundaries. Like border_type=*, the values are not globally unique, so they must be interpreted either literally or in the context of the surrounding country.
Some countries have standardized on country-suffixed keys: admin_type:BF=*, admin_type:FR=*, admin_type:MG=*, admin_type:PH=*. This allows data consumers to evaluate the value without geocoding the feature. In theory, a disputed territory can be tagged with multiple such keys, each representing a different claiming country's viewpoint.
Some countries use official_status=*, which prefixes the value with a country code, so that data consumers can evaluate the value without geocoding the feature. Unlike the admin_type:*=* subkeys, there is a single unified key, which improves discoverability.
place=* points are classified a place according to a global set of values. When these points represent populated places (human settlements), the classification does not necessarily correspond to a formal or legal designation. For example, some place=villages are formally classified as hamlets, towns, districts, or even cities. Over time, place=* has also been added to many boundary relations for the benefit of geocoders. Some of the values appear to match legal terminology (or translations thereof), causing inexperienced mappers to mass-retag place=* based on the legal terms, without regard for the values' definitions in OSM.
Some countries have placed legal designations in subkeys of place:*=*, such as place:CN=*.
protection_title=* indicates the legal designation of a protected area boundary. Unlike border_type=*, this is a freeform key that accepts non-English values, formatted as natural language text.