Specifically, I'm thinking about "politically correct" language, which is certainly a topical issue (what with the US election and Brexit vote) and one likely to land at least a few English Learners in hot water if they are unfamiliar with the cultural standards.
For example, calling women "girls" can be fine, but only in the right context. In many other contexts it is definitely contraindicated. Similarly, it can be tricky to to refer to, or ask about, someone's ethnicity, culture, or religion.
It might be interesting to create a canonical post on this subject or at least ask a "canonical" question to help guide learners who would like to avoid at least the more common pitfalls, but I'm not certain if it is appropriate, or how best to structure it.