Category groups?

I think many people want one more tier of organization, and they don’t necessarily want there to be topics in that category, they just want to be able to, for example say “these categories belong to Mozilla communities” and then have the normal two tiers of categories and sub-categories. So we could have a Communities grouping, and then each community could have its own parent category and sub-categories.

@leo I think we agreed this was the smartest approach. thoughts? Ideas? what skills would people need to help with this?