enclosing geometric object which locates the resource, expressed as a set of (x,y) coordinate (s) NOTE: If a polygon is used it should be closed (last point replicates first point) sets of points defining the bounding polygon or any other GM_Object geometry (point, line or polygon) extent of the resource sets of points defining the bounding polygon or any other GM_Object geometry (point, line or polygon) geographic position of the resource NOTE: This is only an approximate reference so specifying the coordinate reference system is unnecessary and need only be provided with a precision of up to two decimal places western-most coordinate of the limit of the resource extent, expressed in longitude in decimal degrees (positive east) eastern-most coordinate of the limit of the resource extent, expressed in longitude in decimal degrees (positive east) southern-most coordinate of the limit of the resource extent, expressed in latitude in decimal degrees (positive north) northern-most, coordinate of the limit of the resource extent expressed in latitude in decimal degrees (positive north) description of the geographic area using identifiers identifier used to represent a geographic area e.g. a geographic identifier as described in ISO 19112 spatial area of the resource indication of whether the geographic element encompasses an area covered by the data or an area where data is not present extent with respect to date/time and spatial boundaries vertical extent component time period covered by the content of the resource period for the content of the resource vertical domain of resource lowest vertical extent contained in the resource highest vertical extent contained in the resource