The author Peter Callero talks about certain organizations as "fraternal organizations." A fraternity is a group or community of men at a college. So what is a "fraternal organization"?
1) An organized group of men. There are clear "members" and "non-members."
2) a loose collection of friends and friends-of-friends. There are vague boundaries between who is a member of the group and who is not.
3) a government-sponsored political party
4) all of these