Chapter 23 WAN Optimization, Web Cache, Explicit Proxy, and WCCP : The FortiGate explicit web proxy : Explicit web proxy configuration overview
  
Explicit web proxy configuration overview
This section describes:
General configuration steps
Proxy auto-config (PAC) configuration
Unknown HTTP version
Authentication realm
Other explicit web proxy options
Restricting the IP address of the IPv4 explicit web proxy
Restricting the outgoing source IP address of the IPv4 explicit web proxy
 
For explicit FTP proxy options, see “Explicit FTP proxy configuration overview”.
 
For web proxy forwarding server options, see “Proxy chaining (web proxy forwarding servers)”.