If you're talking about inclusion and exclusion from any particular groups, you're going to talk about "shibboleths". It's quite a common term and no more flamboyant than talking about "MathML" or "hyperlinks" on HN.
Or Shibboleth, of course. I'd actually expect quite a few folk here to know the word from the SSO solution.
I don't know, I'm not sure I've ever encountered it before. Since it's rooted in Hebrew, perhaps it has to do with exposure to Jewish vulture, or people that express Jewish culture? Certain Hebrew words have become common in American culture (I would say due to long history of excellent Jewish comedians, from Brooks and Allen to Seinfeld), but others are more esoteric (to my view).
Of course, it's entirely possible it's just my experience, I don't want the above to be taken as me discounting that possibility. That's just how it looks from my perspective with the input I've gotten so far.
Oh, I meant common within the field of social geography. I noted that they'd talk about shibboleths of various sorts (language, accent, dress, manners). I wouldn't expect your average person to know about it but it's not obscure in any way for the type of article this is.
OTOH, I first heard the term it was from working with academic institutions in the UK, because Shibboleth seems to be the favoured form of SSO there (though apparently it came from the Internet2 group, which is US).
So anyone doing SSO or SAML etc would probably have heard the word and you'd have to be fairly incurious not to look it up :-)
Or Shibboleth, of course. I'd actually expect quite a few folk here to know the word from the SSO solution.