If it's worth saying, but not worth its own post, even in Discussion, it goes here.
Gwern has a comprehensive FAQ on dual-n back.
Sorry, it wasn't clear from how I asked the question but I wanted a 2 sentence summary.... Gwern's FAQ is a monumental piece of work but the question is if it is even worth reading 50k words long document about it?
If it's worth saying, but not worth its own post, even in Discussion, it goes here.