Navnerom: http://xmlns.geosciml.org/Borehole/3.0
A borehole is the generalized term for any narrow shaft drilled in the ground, either vertically or horizontally.
A Borehole Collar is a feature corresponding to the start point of a borehole which are often plotted on a map. If a text descripiton of the location is available, it should be placed in the gml:description for that feature. If no GM_Point is available, an OGC nil value (eg; http://www.opengis.net/def/nil/OGC/0/unknown) should be used. Implementers delivering 3-D collar locations should provide and elevation to improve interoperability.