Some of us not only swing swords, we also study & collect them. For those of you who are interested in kantei, which is the identification & appraisal of Nihonto, I highly recommend my friend Markus Sesko's excellent series of posts at

This is a free, ongoing university-level course that will take you from the very basics, all the way through being able to understand how & why tosho (swordsmiths) made their blades over the past 1,000 years. Please feel free to leave feedback.