I swear I saw the answers in that topic? Oh well. And Drognar, what do you mean by question? The red flag means, if it is spam, flag that comment and a mod will delete it. The Up arrow is used for merit worthy comments, which are long, thoughtful, and constructive comments.
Well if you see anything under 10 words click the little flag if you see a really really good comment click the arrow and the box is supposed to help you delete your comments but it doesn't work!