The CULT is an Amateur Press Association.
But not really.
Almost all of fandom's other APAs consist of material printed by the members and sent to an Official Editor for collation and distribution. The CULT, on the other hand, functions more like an open letter between friends because the material, usually -- but not always -- a letter, is sent to a designated Member who edits, publishes, and distributes the Fantasy Rotator (FR, for short) by him- or herself. FRs are published every three weeks by the 13 Members in rotation; which explains why it is called a "Rotator" . . . we'll leave the "Fantasy" part to your imagination.
The CULT's waiting list doesn't work like those of other APAs either. There are two separate lists, and people on the waiting lists are encouraged to participate. In fact people on the Active Waiting List are required to participate (the minimum is one letter to every other FR or one postcard to every FR). CULT publications are distributed to Members and the Active Waiting List. The Inactive Waiting List doesn't have to do anything, although they are often very active. Distribution of publications to the Inactive Waiting List is not required, but anyone who writes regularly will receive most of them.
These oddities don't bother the CULT. We're having fun and figure that it's the other APAs that are out of step. Now you've received your first lesson in being CULTish, your next lesson is not to believe everything that you hear. There was a time when the CULT was, like some fannish Alcatraz, a favorite stomping ground of fandom's literary thugs; this earned Our Little Group the sobriquet of "the nastiest bastards in fandom." We've mellowed a bit over the years but you might bear in mind that unexploded shells from World War I still kill people every year. The other description of the CULT, "a small, uninformed group", is as accurate as it ever was.
In any case, the CULT's main purpose is communication between the Members; and a single Rotator can resemble an episode of a soap opera. If reading an FR makes you feel like you are eavesdropping, so be it; you'll be up to speed soon enough.
The CULT is not an invitational APA. The only membership requirement is the intelligence to work your way through our bureaucratic maze. Don't panic. If some of the twits we have had around could figure it out, so can you. First you must drop a note to the Official Arbiter (OA) telling him that you want to enlist. The OA will append you to the end of the Waiting List pending completion of the second step. That second step is to have material (about a page) published by a Member or an Active Waiting Lister in a CULT publication. Most often, that means writing a letter -- for publication -- to a Member about to publish an FR. Names, addresses, and publishing dates are on the Roster in each FR. Publication day is Monday; the deadline for letters is the previous Saturday. If you don't want to join, you don't have to do any of this.
There are other things that can be said about the CULT (or, as it is known to the cognoscenti, The Bucket or Our Little Group); some of them are even complimentary. If you are interested, anybody listed on an FR Roster page can answer your questions. Or you could just pick a likely spot and dive right in. The acid's fine.