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.

See: Category:Wikipedians (category tree)

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 that group users by participation in Wikipedia; such as participants of a Wikipedia collaborative project, or as a Wikipedia functionary.

This includes groupings of users by participation in a formal WikiProject (e.g. Category:WikiProject Biography participants), or informal collaborative activity (e.g. Category:Wikipedian new page patrollers), and contribution to a portal (e.g. Category:Wikipedians who maintain the Energy Portal). This does not include participation in personal userspace projects.^[6] Wikipedia functionaries are (among others) administrators, and Wikipedia clerks.

• Categories that group users by ability to improve the encyclopedia

This includes groupings of users by technical skill (e.g. Category:Wikipedians who edit audio files) and 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). 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 that group users by knowledge or understanding of a topic

This includes groupings of users by narrow technical expertise (e.g. Category:Wikipedians who understand ParserFunctions) 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 verifiabile, cannot form the basis of an appropriate user category.

• Categories that 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.

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 groupings of users on the basis of something that characterises most or all Wikipedia users (e.g. Category:Wikipedians who use the Internet), or humans more generally (e.g. Category:Wikipedians who walk).

• Categories that are vaguely defined

This includes groupings 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, New Age Wikipedians, Mystic Wikipedians)

• Categories that are overly narrow in scope

This includes groupings 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]

• 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 that 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 that group users on the basis of irrelevant likes

This includes groupings of users on the basis of shared preferences that are irrelevant to encyclopedia-building (e.g. Wikipedians who like red foxes).

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

This includes groupings of users by support for or opposition to a person, object, issue, or idea, especially when they are unrelated to Wikipedia.^[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 groupings of users that are 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 humour (e.g. Citizens of Milky Way).^[12]

• Wikipedia:Guidelines for user categories - an historical guideline proposal.
• Wikipedia:What Wikipedia is not
• Wikipedia:Overcategorization

Wikipedia:User categories for discussion/See also