#netCDF            CDF                Comment
#----              ---                -------
history            Revise_History     // History of revision
_FillValue         FILLVAL            // Fill value 

# The asterisk (*) is a placeholder indicator and its corresponding mapping
# attribute is created in the output file.  The following example creates
# 2 attributes (P1 and P2), if uncommented.  The value
# of P1 and P2 will be "Placeholder 1" and "Placeholder 2", resctively.

#P1                 *                  // Value of P1
#P2                 *                  // Value of P2