Did you consider that "how kosher is it?" (ie by whose standards something is deemed kosher and what those standards are) is necessarily and unavoidably entangled in a discussion board on kosher food? I would suggest that it is possibly the most important aspect of the discussion, as it also involves the Jewish moral imperative not to place a stumbling block in front of a blind person. I see no valid reason to prohibit discussion of how kosher something is articulated in your policy. Don't turn this very valuable board into The Forward for food.