Download a later version of the documentation - it's in there..
Basically, when your APs hear Rogue APs, when RLDP is enabled, your APs will try to associate to the Rogue. If successful (ie, Open Auth) they will try to ping the controller. If the Controller see's it's ping, then the Rogue must be on your network, if it doesn't see it's ping - then the Rogue is either (A) Not on your LAN, or (B) Not able to ping the controller.
HTH,
RA