|Minor civil division identifier from New York State Office of Real Property Tax Services|
|Used on these elements|
|Status: de facto|
|Tools for this tag|
A New York SWIS feature ID is a permanent, unique identifier for a minor civil division, established by New York State Office of Real Property Tax Services (ORPTS). Every county and every incorporated municipality in New York has been assigned a unique six-digit number. All cadastral data maintained by the state government is supposed to include SWIS to identify the lowest-level taxing authority for a parcel. Because SWIS code, plat number, and parcel number, taken together, suffice to identify uniquely any parcel of land, many GIS data sets in New York include SWIS for as diverse purposes as describing the boundaries of aboriginal lands, establishing wildlife management areas, and making wetland determinations.
The SWIS code is used in multiple external databases in New York - essentially, it is the indentifying number for any of New York's counties, cities, boroughs, towns and villages. Because so many state systems use it, it appears to be valuable to include it in OSM to enable clients to join OSM and New York data by a unique key.
FIPS code and gnis:feature_id=* are less useful for the purpose, because both of them involve some ambiguity. A city or town often have separate Federal feature IDs as a 'populated place' (essentially, a node label on a map) and as a census district (an area), and the two are often confused. Moreover, New York has many examples of a township and an adjoining city, or a township and a village and a town (or even a county, township and city or village) being named alike, and previous imports have left chaos where GNIS, FIPS and Wikidata links for one area refer to the articles and objects of another, for example, those from a village referring to the data for the surrounding town of the same name. This sort of confusion is part of the reason that New York adopted SWIS in the first place.
Most uses of this tag are being introduced as part of an ongoing (as of February, 2022) comparison of authoritative minor civil division data from New York State GIS] with the existing boundaries in OSM, most of which came in at different times and by different hands from imports of several inconsistent versions of TIGER data. Progress of the audit of OSM's boundary data against New York's authoritative boundaries may be monitored at Overpass Turbo
How to tag
The ref:us:ny:swis=* tag should be placed on the boundary=administrative relation corresponding to a minor civil subdivision. The value should be the six decimal digits identifying the county or municipality. Optionally, if a place=* node is uniquely associated with a municipality, the ref:us:ny:swis=* tag may be added there as well.
Dozens of villages in New York State are split across township lines. In the case where a village is so divided, a second SWIS code is established for the portion of the village that is in the second township. The state's database, for the land in the second town, has both this code and the so-called dominant SWIS code for the village as a whole. Modeling this relationship has not been attempted in OSM yet. It is imagined that the parts will be modeled as boundary=* relations at admin_level=10 and linked to both the containing town and the containing village as members with role subarea.
The official database contains some anomalies in its nomenclature which will not be carried into OSM. Specifically:
- the unusual administration of the City of Sherrill (whose city charter states that it is to be administered as if it were a village within the Town of Vernon) is coded four times, as 'City of Sherrill', 'Village of Sherrill', 'City of Village of', and 'City of Town Outside of Village'.
- the five boroughs of New York City (which are coterminous with counties) are misidentified as 'City of Manhattan', 'City of Bronx', 'City of Brooklyn', 'City of Queens' and 'City of Staten Island'; these names shall be corrected to 'Borough of ...' in all five. (Note that three of them have different names as boroughs and counties: Manhattan is New York County; Brooklyn is Kings County; and Staten Island is Richmond County.) The counties, with their separate SWIS codes, shall also be retained, since they retain a modicum of independence. All executive and legislative functions, except for a largely ceremonial borough presidency, have been ceded to New York City, but the counties retain a separate judiciary.
The use of 'us:ny' in lowercase is not consistent with current best tagging practice: current convention is that at least the ISO-3166-2 codes for country and principal administrative division should be capitalized. The current plan is to rework these codes in a mechanical edit once an audit of New York administrative boundaries and conflation with NYSGIS authoritative data, still in progress as of 15 March 2022, is complete. At that time, this page will be moved to a version with the correct typographic case.
Finding a feature ID
The minor civil division data set from NYSGIS contains the SWIS codes for all the counties and incorporated municipalities (except for the secondary SWIS codes for parts of divided villages). In addition, minor civil division SWIS codes can be looked up in a table, or by querying the ORPTS web site. Once the ongoing comparison of boundaries between OSM and New York State has been concluded, and a second 'clean up' step has added the subareas for divided villages, OSM should have the complete set, which should need to be updated only at the rare event of a municipality's incorporating or disbanding.