Can also be found here:
For each field of the site configuration, a short description can be found, as seen in the picture below:
Bear in mind that for the Admin allowed networks extra caution should be taken. Using this field, you can restrict Users to access the administrative console from IP Addresses in the Whitelist you specify. As described above, you should provide a comma-separated list of CIDR networks that are allowed to access Console (e.g. "172.16.0.0/12, 192.168.0.0/16") If no value is given, then access is allowed from everywhere.
Ensure that your own public IP address is included, or you'll lock yourselves out when saving.