Chapter 1 What’s New for FortiOS 5.0 : New features in FortiOS 5.0 Patch 4 : NAT46 & NAT64
  
NAT46 & NAT64
Policies and Virtual IPs for NAT46 and NAT64 can now be configured from the web-based manager. For these options to appear in the web-based manager, this feature must be enabled using Feature Select. For more information, see “Feature Select”.
To configure NAT64 policies go to Policy > Policy > NAT64 Policy.
To configure NAT46 policies go to Policy > Policy > NAT46 Policy.