Consider the grammar tag.
Two of its most obvious functions are off-topic at Writers.SE:
- Questions about correct grammar are migrated to English.SE.
- Requests for grammar-proofing as a critique are off-topic.
And indeed, the tag is chock-full of closed and migrated questions.
But there are grammar-related questions that work well with us - this and this are both appropriate.
What can we do with this tag to discourage the obvious, off-topic type questions, and clearly define what constitutes good, on-topic questions? Do we need to resort to definition by exclusion?