In my opinion, every question and answer on this site is supposed to deal with using words and phrases in an English-language context. To further this goal, mention of the pronunciation of words in other languages is fine; if it helps people learn about how to pronounce the word in an English-speaking context, it's great. (The same goes for usage and meaning.)
However, there are certain types of questions that I feel are off-topic, and similar types of questions that I feel are on-topic but tend to attract off-topic answers.
Example off-topic question: "How do I pronounce ---- in Greek?"
Now, in my opinion, there can be better ways to deal with the question than just closing it. I would probably close-vote, but it's equally important to leave a comment to the original poster asking for clarification on what they want. If the actual question is "How should I pronounce the Greek word ---- in an English-language context?" then it's on-topic for ELU, in my opinion, and I would retract my close-vote. If the actual question turns out to be "How did the Ancient Greeks pronounce ----" or "How do the Modern Greeks pronounce ----," then it's clearly off-topic.
My main issue is that the original, ambiguous question often attracts answers that I see as unambiguously off-topic for this site. Without knowing exactly what the original poster wants, people will post things like:
Well, the Ancient Greeks pronounced it /----/ [IPA for reconstructed pronunciation of Attic].
As a native speaker of Greek, I know how to pronounce this! It's /---/ [IPA for modern Greek pronunciation].
I just invented these specific examples. The posters are not always ignorant; the issue I have is that these kind of answers solely describe a foreign pronunciation. In my opinion, this kind of answer is misleading if the original poster's question was about how to pronounce the word in an English-language context. And if the original poster actually wanted the foreign pronunciation, then the question is off-topic. So I see no reason for answers like this to exist; in my opinion, appropriate answers for this site should always also include accurate information on pronunciation or usage in English.
For this reason, I routinely downvote this kind of answer (even if the pronunciation info is accurate for the foreign language), and I generally try to leave a comment explaining why, but I'm wondering if there's anything else that can be done to discourage this. Alternately, if someone disagrees that this is an actual problem or thinks that it's inappropriate to downvote these answers (after all, they frequently do show research effort, and may be useful and clear to some people), I'd appreciate hearing that perspective.