[OSM-talk] open question about boundaries sharing nodes with ways or nodes

[Paul Norman]

On 10/14/2015 1:23 AM, Frederik Ramm wrote:
> You'd have to research how the boundary is defined. If there is some
> sort of legal definition that goes "the boundary has the following
> geometry: from lat/lon A to lat/lon B to lat/lon C...", independent of
> the river or highway, then it makes sense to have two different
> geometries. But if the legal definition goes "the municipality of X
> extends until the middle of the river Y" then it would be wrong to have
> two different geometries in OSM.

There's another possibility, found more commonly in remote areas, and 
not often in Europe: none of the above.

Boundaries are not always rigorously defined, and it may not be set if 
the boundary precisely follows the river or not, or in the case of 
multiple similar branches, which branch is followed.

There's also the case where the boundary is defined to be the river, but 
not follow when the river shifts, or only follow some types of river shifts.