Each web page in Doc5 that display user created content has a category and page name associated with it. These can be almost any text you like to help organise and identify your content.
The combination of category and page name is unique. So while there can be a page of the same name in two different categories, there can be only unique page names in single category. So the following is just fine.
|new zealand fauna||kiwi|
|new zealand fauna||weka|