What Remote Commands Does Coreelec Recognize?

I am using a Popcorn Hour IR remote with a Odroid N2. I am trying to map some special Key commands and I am noticing that not all the commands here work.

Is there a list somewhere of remote commands that Coreelec will recognize?
I have tried KEY_F4 & KEY_POWER2 with failure. When I used the KEY_EXIT, it worked to map what I wanted. But I already use EXIT as an existing button.