One of the painful aspects of lots of wiki engines is that they lack hierarchy.
Using categories is complex for the beginners and not really easy to manage.
And by the way the subcategories are buggy in moniwiki, specially with accented caracters.

I found in a wiki module ( http://www.zonatim.com/modules/wiwimod/index.php?page=WiwimodHomePage) for xoops (xoops.org), a very smart and simple way to promote hierarchy : to ask, in the edit form, to what page the page edited is related to as a daughter.
This simple field forces the user to create hierarchy.

I would be really great to have this function in moniwiki and replace the actual category field by the list of the main hierarchycal pages outlined in a tree.

Would it be difficult to implement ?
(Wiwi the module, I am talking about, is written in php)

Sincerely

SB