Mystery Apple Keys Documented Anywhere?

So, I have had a few instances where unintended keypresses totally change behavior. For example:

• clear key followed by zero toggles overwrite/insert mode
• fn key just on its own switches between keyboards installed
• some mystery combination of keys causes text to go right to left when typing

Are these documented anywhere? My guess is that when in "num lock" mode, the other numbers also do things other than zero changing insert/overwrite.

Note that the above were on a Magic Keyboard with a dedicated numeric keypad.

Thanks!

Regarding the Fn/Globe key switching keyboards, that is a feature introduced with Big Sur. The Fn function is regulated via system preferences > keyboard > keyboard.

The shortcuts for changing text direction are documented here.

I think overwrite vs insert depends on the app.