This article describes Rogue Access Point Detection in FortiOS 5.0 & 4.0.
FortiGate v4.0,FortiGate v5.0
FortiOS v5.00: This is a new feature for both FortiOS 4.0 and FortiOS 5.0 on FortiWifi and FortiAP.
FortiOS Wireless options are contained in System Wireless - Settings and AP Menu or
Wifi Controller -> Wifi Network
Mode can be configured using the following: