An IllegalFormatException of this type is thrown by a Formatter when unknown flags are specified in a format string.

Figure 16-66. java.util.UnknownFormatFlagsException

public class UnknownFormatFlagsException extends IllegalFormatException {
// Public Constructors
     public UnknownFormatFlagsException(String f);  
// Public Instance Methods
     public String getFlags( );  
// Public Methods Overriding Throwable
     public String getMessage( );  
}