@ccc , thanks. 0k, it's not as scary as it sounds. I know it may seem like a simple think not to know about, but there are a lot of things to know about. Whilst it's good to know about, probably better I don't screw with it, at least for now anyway as @JonB points out. I can get into trouble many other ways 😬😱
But I love the quote on the wiki page you linked to.
'If it walks like a duck and talks like a duck, it’s a duck, right? So if this duck is not giving you the noise that you want, you’ve got to just punch that duck until it returns what you expect. "