RC config setting "list of trusted hostnames"

[Hans-Dieter]

just setting up RC and maybe someone can help me how to set the following setting in the config.inc.php  file correct

$config['trusted_host_patterns'] = [ ]

That setting is found in default.inc.php and I would like to incorporate that into my config.inc.php file.

How do I set my host name ?
Like so
$config['trusted_host_patterns'] = ['mail.myhostnamehere.com']

Any help would be appreciated.
Thank you.