Oh sorry. I thought it was just a play area, and I wanted to try out learning some more advanced mediawiki before I went changing my site's pages.
Noted for future. Thanks.
You can make as many subpages as you like - I do that when I'm organising a section afresh. It's an easy way, and can be deleted when you don't need them any more. I also keep a number of pages under my User:Anne space for keeping notes of things and markup that I need to remember. Take a look if you wish - and copy anything useful to you.