A user category is a type of category—a grouping of related pages intended as a tool for navigation^[1][2]—that contains the user pages of Wikipedia users. The technical function of a user category, therefore, is to group the user pages of Wikipedia users who share one or more relevant characteristics. Given this technical function, and considering the principle that Wikipedia is an encyclopedia and not a social networking site,^[3] the purpose of user categories is to aid in facilitating coordination and collaboration between users for the improvement and development of the encyclopedia.^[4][5]

In addition, as with all categories,^[2][4] user categories should not be used as "bottom-of-the-page" notices. If a Wikipedian wishes to have such a notice, they may edit their user page and add the notice in some other way (such as by adding text or a userbox) instead of creating a category group.

Appropriate types of user categories

Quite simply, a user category is appropriate if it has the capacity to facilitate coordination and collaboration between users for the improvement of the encyclopedia. Some examples of types of user categories that are generally appropriate include:

Categories which group users by participation in Wikipedia.

This includes any grouping of users by participation in a Wikipedia collaborative project, such as a formal WikiProject (e.g. Category:WikiProject Biography participants) or informal collaborative activity (e.g. Category:Wikipedian new page patrollers). This does not include participation in personal userspace projects.^[6] This also includes editors entrusted with additional user-rights and/or responsibilities, such as Wikipedia functionaries, administrators, Category:Wikipedia template editors, Wikipedia clerks.

Categories which group users by ability to improve the encyclopedia.

This includes any grouping of users by technical skill (e.g. Category:Wikipedians who edit audio files, Category:Wikipedians who understand ParserFunctions), or by ability to access, produce or understand certain material such as sources or images (e.g. Category:Wikipedians in Algeria, Category:User de, Category:Translators fr-en, Category:Wikipedians who have access to Project MUSE). Any ability that is not relevant to encyclopedia-building, such as the ability to hold one's breath for more than five minutes or to conduct basic conversion of units,^[7] cannot form the basis of an appropriate user category.

Categories which group users by knowledge or understanding of a topic

This includes any grouping of users by narrow technical expertise (e.g. Category:Wikipedian instrument-rated pilots) or a more general familiarity with a subject (e.g. Category:Wikipedian accountants). Any knowledge that is not relevant to encyclopedia-building, such as knowledge of a spouse's reading habits or knowledge that is not verifiable, cannot form the basis of an appropriate user category.

Categories which group users by interest in a subject

This includes any grouping of users by interest in a subject – that is, interest in editing articles related to a certain topic – so long as the topic is not overly narrow or vague (see below: Categories that are overly narrow in scope, Categories that are vaguely defined). Note that merely liking/disliking or supporting/opposing something does not necessarily imply an interest in editing articles related to it. Any interest that is not relevant to encyclopedia-building, such as an interest in eating éclairs, cannot form the basis of an appropriate user category.

Inappropriate types of user categories[edit]

Since the purpose of user categories is to facilitate improvement of the encyclopedia, categorisation on the basis of any characteristic (including particular abilities, interests, knowledge, or skills) that has no or limited relevance to the encyclopedia is inappropriate. Some examples include:

Categories that are all-inclusive

This includes any grouping of users on the basis of something that may be a characteristic of most or all Wikipedia users (e.g. Wikipedians who use the Internet, Wikipedians who use personal computers), or humans more generally (e.g. Citizens of Milky Way, Wikipedian of Earth).

Categories that are broadly or vaguely defined

This includes any grouping of users on the basis of characteristics which cannot be readily identified, or which are defined so broadly or vaguely that one cannot draw meaningful conclusions about users based on their membership in the category (e.g. Wikipedians interested in general knowledge, Wikipedians interested in local history, Wikipedians who play video games, New Age Wikipedians, Mystic Wikipedians)

Categories that are overly narrow in scope

This includes any grouping of users on the basis of a characteristic that limits opportunities for encyclopedic collaboration to just one or very few articles, such as categories for interest in or fondness for a single individual (e.g. Wikipedians interested in Paul McCartney) or film.^[8] This also includes the creation of "personal" categories, in which an editor might wish to group articles, userspace pages, or any other pages categorised by personal preference, such as by user(s) edits or uploads, or even by personal interest.

Categories that are not-based

This includes any grouping of users based on the absence of a particular characteristic (e.g. Wikipedians not active on weekdays, Wikipedians who don't wish to become administrators, Wikipedians who don't own automobiles), including inability to speak a language.^[9]

Categories which group users by dislikes of any type

This includes any grouping of users based on a shared dislike for a person, group, organisation, event, idea, philosophy, or activity (e.g. Wikipedians who dislike High School Musical).

Categories which group users on the basis of irrelevant likes

This includes any grouping of users on the basis of shared preferences that are irrelevant to encyclopedia-building (e.g. Wikipedians who like red foxes, Wikipedians by food preference).

Categories which group users by advocacy of a position^[10]

This includes any grouping of users by support for or opposition to a person, object, issue, or idea if they are unrelated to Wikipedia. There is no consensus on whether categories grouping Wikipedians by non-disruptive statements of opinion on internal Wikipedia matters are allowed.^[11]

Categories that are divisive, provocative, or otherwise disruptive

This includes any grouping of users on the basis of a characteristic that, unintentionally or by design, triggers a negative emotional reaction in others, is detrimental to an environment of constructive collaboration, or brings Wikipedia into disrepute. This includes categories for enmity toward a particular group of people, dislike for or hatred of a particular individual (e.g. Wikipedians who dislike George W. Bush), or support for or opposition to a controversial person, group, project, idea, policy, or activity. This also includes categories created in protest or to make a point (e.g. Wikipedians whose religion has been deleted by Wikipedia).

Categories that are jokes/nonsense

This includes any grouping of users that is patently false (e.g. Wikipedians who are zombies, Wikipedians in their 780s), nonsensical (e.g. Userpages That Are Full Of LOL), undecipherable (e.g. Wikipedians who Watch animals from their POV), or created primarily for humourous or satirical purposes (e.g. Wikipedians who are one of an infinite number of monkeys).^[12]

• Wikipedia:User categories