Hello New to Game, Have a DRM Question

[Faithful]

Hi all just bought the game to support developers that make and provide to users DRM Free games.

I read in a different post that since version 1.1.1 the game has been DRM Free, but I have  a question.

I received my email with a download link (which I did), but it also included a Registration Key number.

Why, would I need a Reg. Key if the game is 100% DRM Free?

I would really like to know the answer to this before I install the game, as I bought the game to support DRM Free games and that is what I am trusting I received.

Thanks

EDIT: OK, I have been looking around and I found this thread, Registration Key Topic.  I think this is the answer I was looking for, so off to install the game now.