Chapter 15 Unified Threat Management for FortiOS 5.0 : Web filter : Deep Scanning Restrictions : Categories Exempt from Deep Scanning
  
Categories Exempt from Deep Scanning
For the purposes of personal privacy, there are 3 categories that can be exempted from deep scanning by the FortiGate unit. They are Banking, Health Care and Personal Privacy.
When HTTPS URL Scan Only is enabled you will notice that the option to exclude these categories from deep scanning is removed. This is because if only the URL is being scanned then the contents of the traffic is not being scanned anyway so there is no need to exclude it.