What exactly does hiding controvesial content block?

I'm trying to find out exactly what is hidden/visible depending on how you have the controversial content option toggled. Is it a collection of tags? if so what are they? I for instance I would love something that blocked all content with the forced tag but not at the expense of the genderbend tag.

Or is there some other metric I'm not aware of for determining if content is controversial?

So what exactly does Fakku consider "Controversial"?

Apologies if this information is available else where but I looked and couldn't find it.

Thanks

- Girbicfluzz