Polygon
From imde.io
A Polygon is a shape on a map that links a number of individual grid references. A Polygon is useful for providing information or data about primary material acquisition (PMA).
Polygons are defined by a set of by latitude and longitude coordinates, in the order the shape should be drawn, where the last coordinate is the same as the first. Below an example:
[0.731300,46.605612 -0.191250,46.704963 -0.191250,46.846894 0.177770,46.988824 0.447438,46.960438 0.589369,46.804315 0.688721,46.832701 0.731300,46.605612 0.731300,46.605612]
You can draw polygons and export them as KML files using Google Earth
