I have been reading a lot of diverging sources on this. So I am relying on you to help me out. It will be used for a programming language akin to CSS.
So that's what we currently have:
Here are the complicate ones:
1/ What's the correct order for these 3?
2/ Does ultrablack corresponds to one of these? Is it a separate weight?
3/ Which one corresponds to 800? 900?