/etc/xdg/autostart/bluetooth-applet-unity.desktop is in gnome-bluetooth 3.2.2-0ubuntu5.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 | [Desktop Entry]
Name=Bluetooth Manager
Comment=Bluetooth Manager applet
Icon=bluetooth
Exec=bluetooth-applet
Terminal=false
Type=Application
Categories=
OnlyShowIn=Unity;
NoDisplay=true
X-Ubuntu-Gettext-Domain=gnome-bluetooth2
|