Currently there is an undergraduate tag. This tag has 1 question. I believe that this tag could be made much more useful by setting a skill level rather than a grade level. There could be an undergrad intro class or a high school advanced class. In summary, should tags references to specific grades levels be changed to beginner or intermediate or advanced or a different tag along those lines?
Based on this thread "Suitable age range tags", I would think so. The quote that stands out to me is this:
Tags are meant to describe the subject of the question, not to specify how it should be answered or of whom it is being asked.
The subject could be functional programming or IDEs or version control, all of which can be addressed irrespective of grade level. As Robert points out, grade/age level tags could muddy the waters significantly.
That said, looking at the Mathematics Educators site, the two most popular tags are for undergraduate and secondary education. Skimming through their meta site, I don't see any discussion related to this topic. Maybe we have an opportunity hear to stay focused on subject/content rather than level. That could also point to an inherent difference between math and CS vis-a-vis levels of education and the users of the sites.
See this answer - https://cseducators.meta.stackexchange.com/a/13/41 which suggests that tagging in this dimension is probably not useful. I'll see if i can edit the question.