The Open Firmware Working Group's website at https://www.devicetree.org/open-firmware/home.html https://www.devicetree.org/open-firmware/home.html mentions the

The Open Firmware Working Group's website at https://www.devicetree.org/open-firmware/home.html https://www.devicetree.org/open-firmware/home.html mentions the OpenBoot(tm) trademark, but uses Open Firmware without any signifier. (and they should know) Given that there's apparently no protection at all, I see no reason why I'd have to adhere to your wish to use 1275's way of writing O and F in upper case. So yes, I _can_ call it open firmware.