What does Packet Logging do under a Remote Desktop List do ?

Ive had a dig around in the documentation and can't find out what enabling packet logs does under a remote desktop profile. This setting is found under Access Policy ›› Application Access : Remote Desktops : Remote Desktops List. The options are either None or Packet.

 

Where are these logs stored and what is stored if this enabled. I've checked the APM, LTM and Messages logs and enabling this option doesn't seem to create any additional logs in these locations.

 

Thanks