Chapter 15 Unified Threat Management for FortiOS 5.0 : ICAP : Configuration Settings : Profiles : Enable Response Processing
  
Enable Response Processing
Enabling this setting allows the ICAP server to process response messages.
If enabled this setting will also require:
Server - This is the name of the ICAP server. It is chosen from the drop down menu in the field. The servers are configure in the Security Profiles > ICAP > Server section.
Path - This is the path on the server to the processing compent. For instance if the Windows share name was “Processes” and the directory within the share was “Content-Filter” the path would be “/Processes/Content-Filter/”
On Failure - There are 2 options. You can choose by the use of radio buttons either Error or Bypass.