This entity is used to provide for area fills. The normal distance between lines is constant and shall not be zero. Wider spaces between lines are to be considered blank lines with regard to normal distances. Boundary curve and islands are closed and not self- intersecting. Island interiors are mutually disjoint.
Islands lie in the interior of the boundary curve.
Boundary curve and islands can be logically dependent and do not need to be marked as annotation if they are not annotation. The drawing entity defines the basic engineering drawing format for each sheet. One drawing entity shall exist in the file for each sheet, or collection of sheets, of an engineering drawing. An example of a collection of sheets would be several B size sheets placed in an H size engineering drawing. All entities pointed to by the drawing entity shall be physically dependent and shall be flagged as annotation.