Thomas Shey
Legend
Yup. Magic circles. You find similar kinds of things in the rest of the country, based on the folks that settled in those areas. The upper midwest had strong Nordic immigration and so you see folk magic of that sort.
The point is: this stuff isn't the purview of formal education, but tradition. Some rube from Hardbottle might not be able to read the runic circle but probably knows what it is.
This can be an important distinction in games that are not class-based and thus have no hard line between spellcasters and not, especially when the latter bleeds into the community commonly. As a notable example, the vast majority of RuneQuest characters know some magic, albeit not high end; in an equivalent setting, I'd expect most characters to at least recognize a protective circle, if perhaps not all the details about it.