AFAIK, Apple's keyboards are the only keyboards that actually report the Fn key to the computer. On other keyboards, the Fn key traditionally toggles layer only

AFAIK, Apple's keyboards are the only keyboards that actually report the Fn key to the computer. On other keyboards, the Fn key traditionally toggles layer only locally on the keyboard, with the layout defined by the keyboard, not the OS. One thing close to it (now that it is also the "Globe key"), would be the Emoji key on some Microsoft keyboards, which sends Ctrl + Shift + Alt + Windows + Space. (same as "Office key" + Space)