Proposed features/Boundary markers proposal
|Boundary markers proposal|
|Proposal status:||Draft (under way)|
|Definition:||Improve boundary markers mapping by consolidate usage of marker key|
It is proposed to introduce marking=* to indicate what the a marker is for. For a boundary marker that would be marking=boundary. The kind of boundary can be added using marking:boundary=* eg. marking:boundary=administrative. marker=* (see https://wiki.openstreetmap.org/wiki/Key:marker) will be continued to be used to tagg the shape of marker.
This proposal focuses on boundaries. This encompasses all kind of boundaries that are mapped in OSM. Not only state borders but also other administrative boundaries, forest compartments, nature reserves etc.
There are existing keys like boundary=marker that should not be used anymore as to not clutter naming intended for the boundary itself.
marking=* is only a first idea how to call the key. Please participate on the discussion page if have a better name.
Boundary markers make invisible boundaries visible. Although they do not need to be exactly on the boundary. Eg if the boundary is in a river or on a road.
Furthermore, boundary markers are great visual helps for navigation or location on unknown places. Refs and colour can help anyone who want to locate on a map.
Currently boundary markers can be marked with boundary=marker but there is no scheme on how to indicate what kind of boundary they mark and the usage of boundary=* for something that is not a boundary itself is not ideal. boundary=marker is currently not explicit on what kind of boundaries it can be used.
Namespacing with marking: allows to distinguish properties of the marker from properties of the boundary. Using wikidata items, data users can connect marker and boundary without the need of a relation in OSM. This proposal is modeled along the lines of https://wiki.openstreetmap.org/wiki/Proposed_features/Utility_markers_proposal.
Having the boundary markers in the database can be useful for mapping boundaries for which no other sources are available.
Here is a summary of recommended tagging for a utility marker
|marker||<marker shape>||The node corresponds to a marker seen on ground||mandatory|
|marking||boundary||Indicates that the marker is a boundary marker. Proposal can be extended with other values for markers of other things.||recommended|
|marking:boundary||<boundary type>||Type of boundary the marker is referring to. Possible values see boundary=*||optional|
|material||<material>||The material composing most of the marker (referring to the support if dedicated)||optional|
|ref||<marker ref>||If available, the ref of the marker itself as it can be read on the marker||optional|
|marking:wikidata||<wikidata>||Eg a nature reserve https://www.wikidata.org/wiki/Q61952725||optional|
|marking:ref||<marker ref>||Ref of the boundary the markers marks||optional|
|marking:name||<marker name>||Name of the boundary the markers marks||optional|
|marking:admin_level||admin_level=* of the marked boundary.||optional|
|marking:protect_class||protect_class=* of the marked boundary. Namespacing indicated that the marker is not protected itself.||optional|
|operator||<company name>||The name of company or authority who operate the marker||optional|
|colour||<colour>||The most representative colour of the marker||optional|
And a list of possible values for marker=* depending of their design. The values have already been approved for utility markers. The proposal changes the descriptions slightly to remove references to utility infrastructure.
|marker||post||Standard kind of marker composed of a pole/mast with useful information written on it. The support have to be dedicated to marker, see plate for other situations|
|aerial||A marker that is intended and designed accordingly to be seen from aircraft.|
|pedestal||Unlike a stone, pedestal are man made and can be whether in plastic or in concrete. Useful information is found on top of them.|
|stone||A stone is a natural support where useful information is directly etched or painted on it.|
|plate||A kind of sign installed on walls or other structures without any dedicated support|
|ground||The marker is directly installed on ground with help of fixation support to hold it in place|
How to map
Once located on ground during a survey or got from public information / street level pictures, just put a node on the exact point and add following tagging on it.
For sake of One_feature,_one_OSM_element, each marker should get its own node on OSM at the exact place it belongs to. If a mapper only knows that it is a boundary marker but not for what kind of boundary marker=* and marker marker=boundary are enough.
Markers will surely indicate that a particular boundary lies next to it. Nevertheless, markers are installed to be seen. So it's not recommended to put markers directly on boundaries, unless you know that the marker is exactly on the boundary.
Values to be replaced
|Obsolete tag||Usage volumetry||New tag(s) to use|
|boundary=marker||17,817 on 2022-09-07||marker=* + marking=*|
|Two post marking an international border. Both of them are not exactly on the border.|
marking:name=Yellow Stone National Park
|Boundary of a national park.|
|A plate marking the boundary of forest compartment.|
Outdoor oriented maps can render as a dot with text for orienteering purposes.
https://community.openstreetmap.org/t/how-to-tag-markers-of-forest-compartments/2322 (My original question on how to tag forest compartment markers) https://lists.openstreetmap.org/pipermail/tagging/2022-August/065146.html (Proposal to use subject=* to indicate what a marker marks, in the context of pipelines)
Please comment on the discussion page.