Help:Categories

The categories in a wiki are pages from the namespace Category:, having one special functionality: to arrange other pages and categories in a category tree. Actually, it may not be a tree, but for the sake of simplicity it is often called in this way.

All editable pages, which means all pages except the special ones are subject to categorization.

Principle of categorization
A wiki utilizes the following principle of page categorization: category definitions are contained in the pages of the category elements (regular pages or subcategories).

For the sake of good organization of the page code, in edit mode these category definitions are usually placed at the end of the document; nevertheless, wherever the definition in the source code has been placed, in read mode categories always appear in the bottom of the webpage.

The inclusion and removal of categories, as well as the shifts in the category tree structure was intentionally made easy, at the price of having a bit more difficult category rename and moving its contents. Another drawback of this principle is that there is no easy way to trace the history of additions and removals of elements to/from a category. However, the practice has showed that both these drawbacks are not crucial and relatively less needed.

A subcategory can be created by only defining its parent nodes. Nodes in the "tree" can be added, removed or rearranged only by adding, removing or replacing category definitions in the subcategory page: it does not involve edits in the pages of the category nodes.

Most wikis prefer to have pages categorized in the deepest relevant categories (which implicitly includes all the parent categories upward the tree). Ifigenia is not going to be so strict about categorization: as long as the category name is relevant to the page contents, it's adequate to have this page categorized there.

Category facilities in Ifigenia
Some software customizations were made on Ifigenia, in order to facilitate its users in associating pages to categories. prompting the user to insert a category name. This approach is more handy when the user knows the precise name of the intended category.
 * Button [[Image:Button category.png|"Insert category" button]] was added and it inserts command: [[Category:]]
 * In case the user does not know the exact category name, they can choose it from the menu between the text box and the save / preview buttons. This facility was made possible via the MediaWiki extension ManageCategories.
 * To browse the category tree, one can use the special page CategoryTree, created by the MediaWiki extension of the same name.