Defines a custom Apache HTTPD access log format string. This option is only consulted when logFormat is set to custom. The value must be a valid Apache LogFormat specification and will be registered under the symbolic name custom. See https://httpd.apache.org/docs/2.4/logs.html#formats for the formal definition of log format directives.

null

"%{X-Forwarded-For}i %l %u %t \\\"%r\\\" %>s %b"