There might be other keys that can't be mapped, but those are the ones I've discovered so far. Games like FFXIV allow remapping these keys and even differentiate between left and right Alt, which is very helpful for players with disabilities or those who need different key binds for whatever reason.

Personally, I'm using my keyboard's software to remap the keys, but this is not a perfect solution since this affects my ability to type until I change the configuration back to default, and most people don't have access to or may have difficulty operating key mapping software outside the game, which can make the experience frustrating.

+1 but where's the "every" key?

Yeah, this is incredibly annoying. I don't use qwerty, and some of the important keys in my layout cannot be mapped - the period key, the semicolon key, and the DELETE key being the ones that come to mind at the moment. So, I'm forced to use the programmable option on my keyboard to muck with the layout for this game just so that I can remap those keys, and it causes problems any time I need to type in chat as well as any time I swap in and out of the game. I have no clue why they limit which keys can be remapped, but aside from something like the ESC key, IMHO everything should be remappable.

Thanks for the reply, I added the Delete key to the request. I recall that I could reassign Delete as well in FFXIV, and confirmed that it can't be mapped in Black Desert.