Specifically, something that allows the following item in the TOS to be removed or eased.
Posting content of any kind that incites discrimination, hate or violence towards one person or a group of people because of their belonging to a race, religion or nation is strictly prohibited.
Inciting 'discrimination, hate or violence' isn't my thing, but clearly it's important to many people who might contribute or increase site activity.
Free speech is an attractive ideal for me and many others - unfortunately following through with it means giving up a lot of website control.
I didn't say invite only. That would certainly lock it down like that. No, it just doesn't show up in /all. That's all it means.