Where can I find out which shortcut key combinations in vim have been used by default and which have not yet been used?

  question, vim

May I know where to find out which shortcut key combinations in vim have been used by default and which have not yet been used?

I hope to have a complete list. I have read the official handbook and have not found it.

The best is the version of gVim under Windows environment.

Thank you!

If you want to set it up, you can read: help map-which-keys first.