There's a local concept known as out of bounds, which is just an expressed public notion of taboo.

As practiced, it can make for uncomfortable situations: while it is OOB to talk about other people's religions, sexual preferences, and politics, a significant number of people think it ok to ask someone where that someone is on those spectra.

Is this because people want to talk about these things and since discussions are OOB, all they have left are labels? Or is this a prequalification question, that then makes it safe-ground to discuss OOB material?

Having grown up in New England, my OOB is almost a perfect mirror image: one can talk religion, sexual preferences, or politics till the cows come home, however asking someone who is not a good friend what they personally believe is grounds for a smackdown. We all believe different things, and civil society is predicated upon the wilful ignorance of our differences.

Of course, these moments are just a fact of life when one lives in a civil society that works on seemingly diametrically opposite principles -- it's just that most of the time you can exist in the pleasant fiction that civil here is the same as civil there.