It came up while working on a recent support request that FAQ 82 (How do I leave a community?) doesn't include information about one community leaving another. Communities are sometimes added to other communities. If Community A is added to Community B, and the maintainer of Community A doesn't want their community to be a member of Community B, they will have to log in as the community and visit Community B's page, then leave it as described in this FAQ. I think it would be a good idea to include in FAQ 82 that, if you are the community maintainer and you're trying to get your community to not be a member of another community, you will need to log in as the community, not the maintainer.
Does this even make sense? How many times did I use the word "community" in that paragraph?