/lib/udev/rules.d/60-libgnuradio-fcd3.7.10.rules is in libgnuradio-fcd3.7.10 3.7.10.1-2+b3.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 | # Funcube Dongle
ACTION=="add", SUBSYSTEMS=="usb", ATTRS{idVendor}=="04d8", ATTRS{idProduct}=="fb56",MODE:="0666", SYMLINK+="FCD"
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