This optional parameter specifies the format that is to be used to log ignored authentication requests in Filename when LogFormatHook is not defined. You can use any of the special characters defined. For more information about special characters, see Section 3.3. Special formatters. Also %0 is replaced by the message severity level, %1 by the reason string and %2 by the tracing identifier. The default value is %l:%U:%P:IGNORE. This logs time stamp in long format, current User-Name, decoded password and text IGNORE.