I have noticed some "non-mainstream" (it may be rude to say crackpot) questions and answers recently such as:
Questions
Answers
What is the kinematics of a particle with complex mass? (screenshot)
Plausible explanations for 3 large space dimensions (screenshot)
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)
Models of neutrinos consistent with OPERA's results (screenshot)
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?