When creating or editing a page, the category can be selected from a menu of existing categories or a new category can be created by typing it's name in a text field next to the menu. By default a page does not have a category (or rather its category is the empty string). You can set the category of a page to the empty string by selecting the first item in the category menu.
If a page has the same title as a category, it is known as the category's home page. In the site map, the category's home page is accessible directly from the category's header.
According to standard social protocols, some categories are often used in Wiki sites: the People category is used for authors, the Trash category is used for pages to be deleted (Wiki pages cannot be deleted, see why in the page on titles). Note that these category names are not predefined in any way - they are just a useful convention.
Let us know in the comments page or in this page how you use categories. For example, does it make sense to put a page into several categories? Or would you like a link from each page to it's category's home page? [mbl]
Version 1, Tue 24 Nov 1998 08:47:08 [mbl]