# allow empty class for USB devices, by appending the interface number
SUBSYSTEMS=="usb", ENV{ID_BUS}=="?*", KERNEL=="event*", ENV{.INPUT_CLASS}=="", ATTRS{bInterfaceNumber}=="?*", \
SYMLINK+="input/by-id/$env{ID_BUS}-$env{ID_SERIAL}-event-if$attr{bInterfaceNumber}"
# allow empty class for USB devices, by appending the interface number
SUBSYSTEMS=="usb", ENV{ID_BUS}=="?*", KERNEL=="event*", ENV{.INPUT_CLASS}=="", ATTRS{bInterfaceNumber}=="?*", \
SYMLINK+="input/by-id/$env{ID_BUS}-$env{ID_SERIAL}-event-if$attr{bInterfaceNumber}"