- It's OSM best practice to have boundary=administrative on the constituent ways of a boundary relation, even if the same information is on the country's boundary relation. See http://wiki.openstreetmap.org/wiki/Boundaries and http://wiki.openstreetmap.org/wiki/Relation:boundary
- However, the OSM default style only renders borders from relations, so a lot of OSM contributors don't know that the tags on the ways are missing.
- Admin_level 2 boundaries on relations (probably no gaps) http://overpass-turbo.eu/s/hcO
- Admin_level 2 boundaries on ways (zoom in and look for gaps) http://overpass-turbo.eu/s/hcN
##Task:
Find ways that are part of boundary relations (specifically, relations that are boundary=administrative and admin_level=2), where the way itself lacks those tags.
Add the following tags to the way:
boundary=administrativeadmin_level=2border_type=nation
Note: frequently when a border follows a river, there's usually a separate way for the boundary, and one for the river. But in these cases, because the rivers and ridges are already part of the boundary relation, it seems okay to add boundary tags to the natural features themselves. There's some precedent here: https://help.openstreetmap.org/questions/7563/waterway-as-administrative-boundary-shared-way, and there are 39K examples of boundary=administrative combined with waterway=*, so I think that's good enough to proceed: https://taginfo.openstreetmap.org/tags/boundary=administrative#combinations
Here are some areas I've spotted that need editing:
This is just from a quick pan around the map. There are probably more spots that we could find with a more thorough search.