This is an information page. It is not one of Wikipedia's policies or guidelines; rather, its purpose is to explain certain aspects of Wikipedia's norms, customs, technicalities, or practices. It may reflect differing levels of consensus and vetting.

Shortcut WP:CATCLASS

A Classification is used on category pages to show the hierarchy of the category. For example, Category:Contraltos has this classification:

The easiest way to create a classification is to use a template if there is one that is appropriate. See the template section below. If there is no template that will work you can add a classification by manually editing a category to insert links. The classification for Contraltos was created with this text:

<div style="text-align:center;">'''Classification: '''[[:Category:Performing arts|Performing arts]]: [[:Category:Theatrical genres|Genres]]: [[:Category:Opera|Opera]]: [[:Category:Opera singers|Singers]]: [[:Category:Singers by voice type|By voice type]]: '''Contraltos'''</div>

<div style="text-align:center;">''also:'' [[:Category:Music|Music]]: [[:Category:Music genres|Genres]]: [[:Category:Opera|Opera]]: [[:Category:Opera singers|Singers]]: [[:Category:Singers by voice type|By voice type]]: '''Contraltos'''</div>

It looks like this:

Notes:

• The classification should be centered on the page (this is what the surrounding <div...>...</div> does).
• The classification goes at the top of the category page, before any ((Cat main)) and other templates and content.
• "Classification:" should be bold.
• Prefix a colon, as in [[:Category..., to make a category appear as a link. If it doesn't appear when you preview, you forgot the colon.
• Remove redundant words from categories (for example: "Singers" instead of "Opera singers" in this example), where this will not result in confusion; the first word of the link shown should be capitalized.
• The last category, the one being edited, should also be bold.
• Important: Decide where to begin the hierarchy. There is a natural starting place for most hierarchies. You don't have to go all the way to Category:Main topic classifications. Pick a high level that is not distantly related to the category. Often, the high level will be at the bottom of several different higher level hierarchies. This is a good indicator of a natural starting place.

Multiple classifications are possible. List the second one on the next line. Instead beginning the line with '''Classification:''' type ''also:''. You don't have to add a classification for every possible hierarchy. Sometimes, the hierarchy is just a link between different hierarchies.

For example: Category:African-American actors is part of the hierarchy under Category:African Americans. It is also a subcategory of Category:American actors. It is one of just a few sub-groupings under American actors (not all ethnicities are subcategories of American actors), and the entries are duplicated in both categories. This is because they are in effect just related categories. Instead of showing that connection as a classification, it might make more sense to just put a link such as See also: Category:American actors.

Another option, when a category is a subcategory of multiple parent categories of the same level, all themselves subcategories of a single "grandparent", is to use commas and "and" to show them all in the classification, in shortened form. The serial comma is recommended, for clarity. Example:

There are several templates to help classify categories (and more on the way). It is much easier to use a template than to set it up manually. Here are the templates that currently exist. See the discussion page for the template for examples of how to use them.

Templates used with people-by-nationality categories

• ((Fooian people)) - for people of a specified nationality. Examples: Category:British people and Category:Samoan people.
• ((Fooian men)) - for men of a specified nationality. Examples: Category:Norwegian men and Category:Zimbabwean men.
• ((Fooian women)) - for women of a specified nationality. Examples: Category:Icelandic women and Category:East Timorese women.

Templates used with occupation categories

• ((Fooian fooers)) - for people of a specified occupation from a specified country. Examples: Category:British architects and Category:German actors.
• ((Nationality by occupation)) - for occupations from a specified country. Examples: Category:Japanese people by occupation and Category:Australian people by occupation.
• ((Occupation by nationality)) - for nationalities for a specified occupation. Examples: Category:Screenwriters by nationality and Category:Essayists by nationality.
• ((Scientist type by nationality)) - For scientists of a specified type organized by nationality. Examples: Category:Geologists by nationality and Category:Biologists by nationality.
• ((Fooian scientist types)) - for scientists of a specified type from a specified country. Examples: Category:Canadian chemists and Category:Dutch cartographers.
• ((Fooian biologist types)) - for biologists of a specified type from a specified country. Examples: Category:Irish zoologists and Category:French mycologists

Templates used with Wikipedia user categories

• ((Usercat)) - for Wikipedia Users of a specified nationality or region.
• ((Usercat replacing)) - A variation of Template:Usercat with an extra message.
• ((Usercat-1)) - for Wikipedia Users of a specified nationality or region in a specified larger region.
• ((UsercatUS)) - for Wikipedia Users of a specified state or territory of the United States.

Templates used with Transportation categories

• ((US bridges by state)) - for bridges located in a specified state of the United States.