- DEBUG
 
          
          Low-level information, mostly for developers.
 
          
        
          - ERROR
 
          
          A handleable error condition.
 
          
        
          - FATAL
 
          
          An unhandleable error that results in a program crash.
 
          
        
          - INFO
 
          
          Generic (useful) information about system operation.
 
          
        
          - UNKNOWN
 
          
          An unknown message that should always be logged.
 
          
        
          - WARN
 
          
          A warning.