Things that don't belong in questions
Answers! Keep questions in the questions section and answers in the answers section. And yes, you can answer your own question.
Why?
- People skimming the Q&A might miss it
- It's not possible to vote twice for a post, so you don't get any additional rep for it ;)
- If it's wrong, people might downvote your question undeservedly
- Ultimately, Stack Exchange works on the basis of questions and answers (or in another respect, problems and solutions, respectively)
For editors, you can go ahead and remove the answer yourself. Then, if it's worth keeping around (doesn't duplicate any existing answer, etc.), encourage the OP to post it, or post it yourself as a community wiki answer if OP is inactive or doesn't reply after a few days.
"Urgent" or anything like that. This is a Q&A network, not a help desk, and almost everyone here is a volunteer. The best way to get help fast is to ask a good, interesting question with a good title and the right tags. See the How to Ask guide for the site you're asking on.
- See also Under what circumstances may I add "urgent" or other similar phrases to my question, in order to obtain faster answers? - Meta Stack Overflow
"Do you need any more details?" or anything like that. - We'll let you know :) This is implied.
Implicit questions, like "Can someone help me?" or "Does anyone know the answer to this?"
If you've already written a good question, there's no need to tack on an extra one.
This also includes obvious statements, like "I have a question" or "I need help". After all, that's the reason you're posting :)
- Related: Why is "Can someone help me?" not a useful question? - Meta Stack Overflow - For if you haven't written a good question yet