What is happening here? Why is the tag appearing in the tag list and when editing questions, and with a different count of questions to boot? Is it the expected behavior?
(I'm asking because I was editing a question involving a trigonometric function, and kept editing the tag trigonometry back to trigonometric-functions, wondering what was happening... In any case it's annoying behavior, and if it's not a bug I'll consider making this into a feature request.)