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

Classification: Performing arts: Genres: Opera: Singers: By voice type: Contraltos
also: Music: Genres: Opera: Singers: By voice type: Contraltos

How do you create a 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:

Classification: Performing arts: Genres: Opera: Singers: By voice type: Contraltos
also: Music: Genres: Opera: Singers: By voice type: Contraltos

Notes:

Can a category have multiple classifications?

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:

Classification: Sports: Individual, Indoor, Precision, and Ball games: Cue sports
also: Games: Of physical skill, Of mental skill, Ball, and Pub games: Cue sports

Using templates to classify categories

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

Further information: Wikipedia:Categorisation of people

Templates used with occupation categories

Further information: Wikipedia:Categorisation of people

Templates used with Wikipedia user categories

Further information: Wikipedia:User categorisation

Templates used with Transportation categories