My understanding of this is that mathematics is research-level if:
- you could conceivably write a paper on some aspect of it;
- it could be taught in a grad-level course;
- it is not widely known throughout the mathematical community, etc.
(This is by no means a comprehensive or exhaustive list.)
With this in mind, would this questionthis question be acceptable for MO? I'm not sure if this is too far from research-level mathematics to be considered acceptable.