I know the differences between mathoverflow and math-stack but I have been wondering:
Are there legitimate mathematical questions that would not get answered at math-stack because there is no expertise around and yet would be considered trivial (not research level worthy for mathoverflow?)
I agree that the fact that a question that is not answered at math-stack should not be "upgraded" to mathoverflow but is there some other site that covers a middle ground? Is there a place one can ask clarification questions about material covered in PhD math classes?
If you allow me to illustrate, I posted this question https://math.stackexchange.com/questions/554397/effect-of-pullback-of-differential-forms-on-an-ideal that I think is perhaps too trivial for the overflow crowd but that despite a bounty about to expire is languishing at math-stack. I'm afraid there is no good site for type of questions that are appearing in my self-study. Thanks for any feedback.