You're on Stack Overflow and you've found a question that seems to be about improving code. You are trying to be helpful, and you put a comment in the question:
You should try asking on CodeReview.SE instead. —YourName 2 minutes ago
… and suddenly, out of nowhere CodeReview.SE users swoop in saying:
@YourName No, this isn't a good question for Code Review. —AnotherName 5 seconds ago
or they might say:
@YourName This could be a good question for Code Review, if (…) —AnotherName 5 seconds ago
Why are they saying that this isn't a good question, as it is, for Code Review? What is in scope on Code Review?
What should I look for when determining if a question should go on Code Review? And why do they sometimes seem to get so annoyed about the referral?
This question is Code Review's version of a similar question on Software Engineering MetaSoftware Engineering Meta.