This page lists all groups, sorting them by primacy factional allegiance (if any). Groups, unlike factions, are smaller, sometimes player-created bands of characters who share a much more precise goal and function than the factions normally do, and obey their own internal hierarchy. If you've just created a new group, or one seems to be missing from the list, a new group page can be made on the Page Creation page.
In order to show up in a group's automated roster, a character's page needs to have the group properly added to its Groups: field.
This file is public knowledge in-universe, or could be uncovered with a very little bit of digging. It is based on reputation and hearsay, but is accurate enough to give characters apping into one of these groups a general overview of what they might logically know.
Please note that not all of these groups will be separate, coded +groups, and that some may exist only as divisions within the factions themselves.