Chapter 1 What’s New for FortiOS 5.2.1 : Managing Devices : Default Device Groups
  
Default Device Groups
The predefined device groups have been changed to the following:
Windows PC (includes Windows servers and computers but not tablets or phones)
Mac
Linux
Printer
Mobile devices (includes tablets and phones from all vendors)
VoIP phones
Router/firewall/gateway devices (does not include switch devices)
Other (for unknown devices)
To improve accuracy, device types are now identified using UIDs instead of MAC addresses.