There are no unwritten official rules.
"What is the Bible Thumper Caucus?"
Since this requires an actual distinct group to exist, as Catholic, Protestant, evangelical, Calvinists, Pentecostal, SDA, etc. in order to define persons as belonging to it, while Bible Thumper is too amorphous to define members aside from the uninterested (like the poster who criticized the thread), then it is more of a facetious, humorous reference than an enforceable label. "The terms used in a caucus label are not necessarily precise with reference to Canon Law, theology or even dictionaries – but are intended to communicate briefly who should or should not post on a thread."
"Is there a list of religion caucuses?"
No, but example of "Catholic Caucus” gives you an idea of how a "caucus” label can be fitting.
"I think I understand the Catholic Caucus very well, "
Yes, although it excludes Sedevacantists, Orthodox, SSPX and Inactive Catholics.
Thank you for the reply. You said there are no unwritten official rules. I can see that especially since when someone is engaged in hurtful behavior they seem to get a warning and if they control themselves, there will be no further mention of it.
Other than what is written on the Religion Moderator page, I know that there are some posting guidelines on the FR Home page, and I have also looked through Jim Robinson’s comment and post history and read what he has said. I would be happy to read anything else you recommend.
There are subjects of interest to me here, where opposing views squelch any useful discussion almost immediately. Would it be appropriate for me or anyone to attach a caucus label to my own posts? You are reluctant to seem to be making rules, which is understandable, but I would appreciate the benefit of anyone’s experience. I hate to learn things the hard way. It may be better to avoid the caucus designation and just let the chairs fly across the room. Fine with me, and whatever brings out the truth.
Certain there is one unofficial rule which people like Humblegunner have enforced passionately, the prohibition against posting anything associated with a blog. I do not recognize moderators enforcing this except that such posts are moved to bloggers and personal. I cannot say but I think that HG is somewhat begrudgingly appeased by this.
Thank you for your kind help and thanks for your contribution here. It really is a gift to the ungrateful, which God will reward.