Hi Anton,
On 26 Nov 2015 at 18:26:58, Anton Hughes (ah@tradeworks.io(mailto:ah@tradeworks.io))
wrote:
  Hello
 In a Mediawiki page, a user can added [[category:my category]], and the
 page will be accessible from the 'my category' category. The same page can
 be added to many categories.
 The nested page concept seems to be hierarchical only, so a page belongs in
 a tree, but cannot therefore be in other trees. 
I think this is similar to tags:
http://extensions.xwiki.org/xwiki/bin/view/Extension/Tag+Application
  Also, in Mediawiki, there is the possibility (
 
https://meta.wikimedia.org/wiki/Help:Embed_page) to embed pages ? I have
 tried using the mediawiki syntax for this but it does not seem to work. 
See:
* 
http://extensions.xwiki.org/xwiki/bin/view/Extension/Include+Macro
* 
http://extensions.xwiki.org/xwiki/bin/view/Extension/Display+Macro
Thanks
-Vincent
  Anton Hughes