The title is pretty straightforward, this has to do with the FFXIV client. It will not recognize the function keys F13 to F24 and report "unable to bind this key" type errors when you're trying to assign them in the keybinds in windows 10 (and probably every other OS).

Quite a few old keyboards and some current day "extended" keyboards have these keys. Also with the rising popularity of mmo gaming mice with 15+ buttons it isn't uncommon to want to bind these keys to the mouse in order to leave the rest of the keyboard open for the multitude of possible keybind shortcuts FFXIV allows.

As a recap there are 9 hotbars of 12 slots > 108 slotsto potentially bind. Most letters are already attributed to opening logs/features so we don't use them. The NUM pad in windows does not play well with Shift/Alt/Ctrl + NUM as some of those are attributed to windows functions. We're essentially left with binding 1-0 and F1-F12. The later are sometimes already used for other system wide features. This makes F13-F24 pretty precious.

I would also think that it shouldn't be too hard to allow these to be used as they are already supported by windows and mac though mac calls F20-F24 something else.
I guess it would be simpler to just ask if FFXIV could work with all virtual keycodes.

Thanks for reading through that!