I have noticed some "non-mainstream" (it may be rude to say crackpot) questions and answers recently such as:
What reasons are there to suspect string theory may be an incorrect theory? (screenshot) (an instance of calling rather mainstream theory, string theory as fringe)
Currently, I am flagging these as "spam" because they are pretty much like advertisements but isn't it better to have a more specific flag associated with these, like "Non-mainstream"? Since "Spam" usually refers to answers like "me too! I would like to thank so and so website for leading me here" or "me too! So and so company can help you!" etc.
So, has this "Non-mainstream" -flag been proposed before? And what are your thoughts about it?