Border type is used to mark the difference between different types of borders of a speciffic group.
Border type is used to mark the difference between different types of borders. It is used in different ways by different groups of mappers (which is confusing)
Be aware that the main means of classifying borders is to use admin_level=*
An import of US states has used an extension, border_type=* to give the name of the boundary's type. Currently-known values are:
An import in china used the values: