NSE4_FGT-7.2 Practice Test

This is true because Internet Service is a special type of destination object that can only be used alone in a firewall policy. Internet Service is a feature that allows FortiGate to identify and filter traffic based on the internet service or application that it belongs to, such as Facebook, YouTube, Skype, etc. Internet Service uses a database of IP addresses and ports that are associated with each internet service or application, and updates it regularly from FortiGuard. When Internet Service is selected as the destination in a firewall policy, FortiGate will match the traffic to the corresponding internet service or application, and apply the appropriate action and security profiles to it. However, Internet Service cannot be combined with any other destination object, such as IP address, FQDN address, user or user group, etc., as this would create a conflict or ambiguity in the firewall policy. Therefore, no other object can be added if Internet Service is already selected as the destination in a firewall policy

Reference: https://docs.fortinet.com/document/fortigate/6.0.0/handbook/554066/firewallpolicies