While browsing some questions I found this one where a banner appeared just above the comments section, that indicates:
We're looking for long answers that provide some explanation and context. Don't just give a one-line answer; explain why your answer is right, ideally with citations. Answers that don't include explanations may be removed.
I have never noticed this kind of banners before. Why and how was that banner added to the question?
Also, in what cases are those banners added to questions? I see that the mentioned question already had some long answers before I noticed the banner. I am trying to understand the purpose and benefits of banners here in TWP, so I apologize if this is just my misunderstanding.