Help:Categories

Template:PD Help Page MediaWiki enables you to categorize pages and files by appending one or more Category {{#ifeq:Category|Category||(Category)}} tags to the content text. Adding these tags creates links at the bottom of the page that take you to the list of all pages in that category, which makes it easy to browse related articles.

Adding a page to a category

To add a page or uploaded file to a category, simply edit the page and add the following text (where Name is the name of the category you want to add it to).

[[Category:Name]]

Any number of Category tags may be added to the page and the page will be listed in all of them. Category tags are usually added at the very bottom of the page for the convenience of other editors.

Sort key

By default, a page is sorted under the first letter of its full name including the namespace. Also, MediaWiki groups accented characters separately from their unaccented version, so pages starting by À, Á, Ä, will be listed under separate headings, instead of under heading A.

A sort key specifies under which letter heading, and where in the category list, the page will appear. You can add a sort key by placing it inside the tag after a pipe character. For example, the tag below will add the page under heading "S".

[[Category:Name|Sort]]

Sort keys are case-sensitive, and spaces and other characters are also valid. The order of the sections within a category follows the Unicode sort order. The sort key does not change the page title displayed in the category.

Creating a category page

Categories exist even if their page has not been created, but these categories are isolated from others and serve little purpose for organization or navigation.

A category is created by creating a page in the Category: namespace. A category page can be created the same way as other wiki pages (see Help:Starting a new page); just add "Category:" before the page title.

To avoid extra work, try searching within your wiki before creating a new category. The list of all categories can be found in "Special pages" in the "wiki Toolbox" box of the sidebar.

Unlike other wiki pages, it is not possible to rename (move) a category. It is necessary to create a new category and change the Category tag on every page. The new category will not have the older category's page history, which is undesirable if there are many revisions.

Managing the category hierarchy

Categories may belong to other categories in a hierarchy. Since category pages are much like any other page, a Category tag may be added to the bottom of a category page.

It is a good idea to organize all categories into a hierarchy with a single top level category. The category structure can take the form of a tree with separate branches, but more often will have a graph structure. Generally, there should be a contiguous chain of parent-child links between each category and the top level category.

Hidden categories

The categories that a page is in are normally listed at the bottom of the page. A category can be hidden from this list by adding the magic word "__HIDDENCAT__" to the category page. Hidden categories are not hidden from category pages (Template:Bugzilla).

Users can choose to see hidden categories in a separate "Hidden categories" list, by checking "Show hidden categories" in the "Appearance" section of Special:Preferences.

Hidden categories are automatically added to Category:Hidden categories. This category is specified in the system message MediaWiki:Hidden-category-category.

Linking to a category

To create a link to a category, use a leading colon before the category name (without this colon, the current page would be added to the category):

[[:Category:Help]] → Category:Help

To change the link text, write the text inside the link tag after a pipe:

[[:Category:Help|Help category]] → Help category

Redirect pages that redirect to categories must also use the colon, otherwise they will be added to the category instead of redirecting.

Redirecting a category

Like normal wiki pages, category pages can be redirected to other normal or category pages.