Alright, after a quick search, "nkkd315" doesn't come up with much. Maybe it's a typo or a very niche tool. Sometimes people mix up letters in search terms, so maybe it's actually "Nakadai" or "nkcd315"? Wait, no, that doesn't make sense. Maybe it's a custom or internal tool used by a specific company or developer. In that case, there might not be public documentation.