The in-group is comprised of those who post regularly, who are recognized, and who recognize each other. You can tell by the way certain people exercise authority, and the way other people treat them. It's not fixed and it's subjectively determined. Each person might have a different idea of who's in the in-group, though we can probably agree that certain members are more likely to make the cut than others.
Edit: On second thought, forget all that. If you want to be in the in-group, you can send me a PM with $50. I'll getcha in.
Who said you were part of the in-group Guff? Just for that, you're excluded too!
Not to point you out specifically, fidelia, but what you did here indicates to the reader that you have a familiarity with MacGuffin by calling him "Guff".
These signs are not always as obvious, but the forum is peppered with such clues that one can use to see what groups exist, both large and small. Some people keep them more secret; others make their affiliations clear.
There's not just one group either, there are layers upon layers of groups, sub-groups, fringe-groups, wanna-be in the groupies etc.
I'm not passing judgement on that; it just is.
"Remember always that you not only have the right to be an individual, you have an obligation to be one."
― Eleanor Roosevelt
"When people see some things as beautiful,
other things become ugly.
When people see some things as good,
other things become bad."
― Lao Tzu, Tao Te Ching