The Settings page in POLICY | Rules and Policies > Settings > GEO-IP | Settings provides a group of settings that can be configured for Geo-IP Filtering. Several of the settings have (information) icons next to them that give screen tips about that setting.
Security Policies can be configured with Geo-IP set to a particular country(s) and have them blocked to achieve this behavior.
To enable Policy-based settings
To enable Global settings
Enable Custom List - This option is disabled by default. Custom lists are sometimes used to correct a false country assignment for an IP address. When the checkbox is selected, Override Firewall Countries by Custom List is made available.
Override Firewall Countries by Custom List - This selection is only available when Enable Custom List is enabled. It allows your custom list to override the firewall list where there are differences. Unless you select this Override, the firewall list takes precedence, even when you have enabled a custom list.