Salt Variables and documentation

Hello,
I am trying to understand how the Salt Variable (Configure -> Salt -> Variables) are working.

There is a documentation button, but it point to a “Page not Found” error and backtracking every version of the Salt Plugin, I couldn’t find any documentation at all.

What are Salt Variable supposed to be?
Another set of variables over the Hostgroup parameters, host parameter and global parameter?
A way to filter variable coming from hostgroup or host parameter to be included in the pillar?

Any help regarding the usage of that feature, or a link to a working documentation/exemple, would will be welcome.

What I’m trying to do is filter variable out of the pillar, so that I can declare them empty in the hostgroup and have people fill them as required in the host.

Thanks,
Philippe Busque

This is a good question for @Bernhard_Suttner

He talked about its plans for it at Open Source camp #4. I tried to pick the right point of the video, but perhaps the whole things is worth a look for you: