v2_issue4"></a>Coordinate Variable Attributes:</strong><br />
If a coordinate variable contains longitude, latitude, depth, elevation, date, or time values then the units attribute is mandatory; it is used to determine the orientation of the coordinate variable. The long_name attribute is optional but may be used to enhance clarity and the self-describing nature of the netCDF file. Since coordinate variables may not contain missing values the attributes _FillValue and missing_value may not be used with coor