3.5. Flags

The attributes flag_values and flag_meanings are intended to make variables that contain flag values self describing. The flag_values attribute is the same type as the variable to which it is attached, and contains a list of the possible flag values. The flag_meanings attribute is a string whose value is a blank separated list of descriptive words or phrases, one for each flag value. If multi-word phrases are used to describe the flag values, then the words within a phrase should be connected with underscores.

Example 3.3. A flag variable

  byte current_speed_qc(time, depth, lat, lon) ;
    current_speed_qc:long_name = "Current Speed Quality" ;
    current_speed_qc:_FillValue = -128b ;
    current_speed_qc:valid_range = -127b, 127b ;
    current_speed_qc:flag_values = 0b, 1b, 2b ;
    current_speed_qc:flag_meanings = "quality_good sensor_nonfunctional 
                                                     outside_valid_range" ;