The Japanese Language Proficiency Test, or JLPT for short, is a standardized test used to measure skill in the Japanese language of non-native speakers. The current JLPT (revised in 2010) consists of five levels called N1 to N5, with N5 testing the basic-level materials and N1 testing the advanced-level materials.
When should I use this tag?
When asking about a grammar point covered by the JLPT?
When asking whether a grammar point is covered or not by the JLPT?
when asking about the JLPT itself? For instance "Can I take the JLPT test in Bishkek?"
Most of the jlpt questions seem to be in the first case.
Anyway, I think the tag description should be clarified.
To me, cases 2 and 3 both are off topic. The only case I can think of that would merit using the JLPT tag would be when asking about something specifically related to something that might appear on the test, help understanding a sample question, etc. That said, such a tag is really more of a meta classification, and in my opinion could be deleted entirely with little impact on the quality of the site. It's best to avoid superfluous tags.