The user may define subclasses of this class.
The lineage or history of the data may be given through the instances of this class. The data source includes any fieldwork, imagery, positioning, etc used to create the data. Any compilation steps are given under compilation history. Software processing procedures used on the data may include interpolation, smoothing routines, filtering routines, geometric rectification (including relief displacement correction) methods, classification techniques, etc. Lastly, comments may be given.