After reading this and several other meta posts, it seems that one of the most important distinctions to be made on this SE is the distinction between questions which should be answered with as hard, logical, science as possible, and those which either, by their nature, demand extra-scientific/magical answers or at least a lot of fudging of the physics involved. Because of this, I suggest that magic is renamed to magic-based, to better distinguish and contrast with the popular science-based.
Possibly there should be a second tag for soft scifi worldbuilders who don't want magic used, but do not require or would actually prefer that the science is not limited to what we know for sure: any type of well-defined phlebotinum or highly speculative 'science' (dark matter, gratuitous nanomachines, crystals with special properties). I would call this tag speculative-based or speculative-science-based, maybe even [tag;pseudoscience-based], but I don't know if it's necessary or desired.