 | Esta página documenta una guía de edición de Wikipedia en inglés . Es un estándar generalmente aceptado que los editores deben intentar seguir, aunque es mejor tratarlo con sentido común y pueden aplicarse excepciones ocasionales . Cualquier modificación importante de esta página debe reflejar el consenso . En caso de duda, discuta primero en la página de discusión . |
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Esta página contiene orientación sobre el uso adecuado de la función de categorización en Wikipedia. Para obtener información sobre la mecánica de la función, la sintaxis de la categoría, etc., consulte Ayuda: Categoría . Para obtener respuestas rápidas, consulte las preguntas frecuentes sobre categorización . Para propuestas para eliminar, fusionar o cambiar el nombre de categorías, siga las instrucciones en Categorías para discusión . Úselo antes de emprender una nueva categorización complicada de las categorías existentes o la creación masiva de nuevas categorías.
El objetivo central del sistema de categorías es proporcionar enlaces de navegación a las páginas de Wikipedia en una jerarquía de categorías que los lectores, sabiendo esencial- definir -características de un tema, puede buscar y encontrar rápidamente conjuntos de páginas sobre temas que están definidas por esas características.
Las categorías no son el único medio de permitir a los usuarios explorar conjuntos de páginas relacionadas. Otras herramientas que se pueden utilizar en lugar de categorías o junto con ellas en casos particulares incluyen listas y cuadros de navegación. Para una comparación de estas técnicas, consulte Categorías, listas y plantillas de navegación .
Convenciones de nombres
Al nombrar una categoría, se debe tener especial cuidado y elegir su nombre con precisión. Mover páginas categorizadas de manera no convencional a otro nombre de categoría (consulte {{ Redirección de categoría }}) impone una sobrecarga adicional: una edición para cada artículo y subcategoría.
Convenciones generales
- Se aplican las convenciones estándar de nomenclatura de artículos ; en particular, no use mayúsculas en los sustantivos regulares excepto cuando vengan al principio del título.
- Los nombres de las categorías de temas deben ser singulares, normalmente correspondientes al nombre de un artículo de Wikipedia. Ejemplos: " Derecho ", " Francia ", " Hillary Clinton ".
- Los nombres de las categorías establecidas deben estar en plural. Ejemplos: " Escritores ", " Pueblos de Polonia ".
- Evite las abreviaturas. Ejemplo: " Categoría: Equipo militar de la Segunda Guerra Mundial ", no "Categoría: Equipo militar de la Segunda Guerra Mundial". Sin embargo, las abreviaturas que se han convertido en el nombre oficial o de uso general (como OTAN ) deben usarse cuando no haya otros conflictos.
- No escriba la estructura de la categoría en los nombres. Ejemplo: " Monarcas ", no "Personas - Monarcas". Esto incluye la creación de categorías que son subpáginas de otras categorías.
- Elija nombres de categorías que puedan ser independientes, independientemente de la forma en que una categoría esté conectada a otras categorías. Ejemplo: " Talones de terminología geográfica ", no "Terminología" (una subcategoría de " Talones de terminología geográfica ").
- Al igual que con las listas , evite los adjetivos descriptivos como famosos , importantes o notables en los títulos de las categorías.
- Particularmente para temas técnicos, use palabras y frases que existan en fuentes confiables, de modo que esas fuentes puedan usarse para respaldar la inclusión de artículos.
- Cuando el tema de un artículo requiere desambiguación, cualquier categoría con el mismo nombre de ese tema debe incluir la misma forma de desambiguación, incluso si es probable que ningún otro artículo tenga una categoría epónima.
Convenciones especiales
- Tenga en cuenta que en muchos casos una categoría de tema y una categoría de conjunto tienen nombres similares, siendo la categoría de tema singular y la categoría de conjunto plural. Por ejemplo, la ópera es una categoría de tema (que contiene todos los artículos relacionados con el tema), mientras que Óperas es un conjunto de categorías (que contiene artículos sobre óperas específicos). Tenga cuidado de elegir el correcto al categorizar artículos.
- Si hay muchas listas en un área temática en particular, puede ser útil tener una categoría para contenerlas, llamada algo así como " Categoría: Listas de países ". Estas categorías solo deben contener páginas de lista (por ejemplo, " Lista de repúblicas soviéticas ", " Lista de países por población "). Cuando coloque páginas en una categoría de este tipo, utilice una clave de clasificación que excluya la frase "Lista de" (de lo contrario, todas las listas aparecerían debajo de "L"). Consulte también Categoría: Listas .
- Todas las categorías de WikiProject deben tener "WikiProject" (o "WikiProjects") como parte del nombre. Tenga en cuenta que esto no se aplica a los nombres de categorías que los proyectos podrían crear para el uso de evaluaciones. En estos casos, se recomienda el asesoramiento dado en Categorías de proyectos , que se ajusta a las evaluaciones de Categoría: Wikipedia 1.0 , aunque no es obligatorio.
- Las categorías utilizadas para la administración de Wikipedia tienen el prefijo "Wikipedia" (sin dos puntos) si es necesario para evitar confusiones con las categorías de contenido. Por ejemplo, Categoría: páginas de proyectos inactivas (donde no es probable que haya confusión), pero Categoría: herramientas de Wikipedia (a diferencia de la categoría de contenido Herramientas ).
- Directrices de nomenclatura para las subcategorías de Categoría: Las categorías de códigos auxiliares se enumeran en Wikipedia: Orden de códigos auxiliares de WikiProject / Directrices de nombres # Categorías .
- Para la categorización en el espacio de usuario, consulte Wikipedia: Categorización # Espacio de nombre de usuario y Wikipedia: Categorías de usuario # Convenciones de nomenclatura .
- Para las solicitudes de fotografías geográficas, el nombre de la categoría debe ser "Fotografías solicitadas por Wikipedia en xxx" como en [[Categoría: Fotografías solicitadas por Wikipedia en Inglaterra]]. Los Wikiprojects que deseen realizar un seguimiento de los artículos que necesitan fotos deben utilizar "artículos xxxx que necesitan fotos" como en [[Categoría: artículos de Inglaterra que necesitan fotos]] y [[Categoría: artículos de Inglaterra que necesitan imágenes]] (para fotos, mapas, dibujos, etc. ).
Creando páginas de categorías
Una vez que haya determinado un nombre de categoría apropiado y conozca su categoría principal, estará listo para crear la nueva categoría. Para crear una categoría, primero agregue un artículo a esa categoría. Haga esto editando la página del artículo. En la parte inferior, pero antes de los enlaces interwiki (si hay alguno), agregue el nombre de la nueva categoría, (por ejemplo [[Category:New category name]] :) y guarde su edición. El nombre de la categoría aún no definido aparecerá ahora como un enlace rojo en la lista de categorías del artículo en la parte inferior de la página.
A continuación, para crear la categoría, haga clic en ese enlace rojo, que lo lleva de nuevo al editor. Agregar esta nueva categoría a la categoría principal adecuada es muy similar a un artículo: en la parte inferior, simplemente agregue la categoría principal (por ejemplo :)[[Category:Parent category name]] , que normalmente debería ser un hiperónimo de la subcategoría.
A veces, una suposición de sentido común basada en el título de la categoría no es suficiente para determinar si una página debe incluirse en la categoría. Por lo tanto, en lugar de dejar el texto de una página de categoría vacío (que contiene solo declaraciones de categoría principal), es útil, tanto para los lectores como para los editores, incluir una descripción de la categoría, indicando qué páginas debe contener y cómo deben subcategorizarse. , y así.
En tales casos, el contenido deseado de la categoría debe describirse en la página de la categoría, de manera similar a como se describen los criterios de selección de la lista en una lista independiente. La descripción de la categoría debe hacer declaraciones directas sobre los criterios por los cuales las páginas deben seleccionarse para su inclusión (o exclusión) en la categoría. Esta descripción, no el nombre de la categoría, define el contenido adecuado de la categoría. No deje que los futuros editores adivinen qué o quiénes deberían incluirse en el título de la categoría. Incluso si los criterios de selección pueden parecerle obvios, un estándar explícito es útil para los demás, especialmente si están menos familiarizados con el tema.
La descripción también puede contener enlaces a otras páginas de Wikipedia, en particular a otras categorías relacionadas que no aparecen directamente como subcategorías o categorías principales, y a categorías relevantes en proyectos hermanos , como Commons . Otra técnica que se puede utilizar se describe en Wikipedia: Clasificación . Al igual que las páginas de desambiguación , las páginas de categorías no deben contener citas de fuentes confiables ni enlaces externos .
Se han desarrollado varias plantillas para facilitar la producción de descripciones de categorías; consulte Plantillas de espacios de nombres de categorías . Hay plantillas de notas que incluyen {{ Cat main }} y {{ Category see also }}; otros se enumeran en Wikipedia: Hatnote # Categorías .
Se muestran un máximo de 200 entradas de categoría por pantalla. Para facilitar la navegación por categorías grandes, se puede utilizar una tabla de contenido en la página de categorías. Las siguientes plantillas son algunas de las formas de hacer esto:
- {{ Category TOC }}: agrega una tabla de contenido completa (superior, 0–9, A – Z)
- {{ TOC de categoría grande }}: agrega una tabla de contenido completa con cinco subdivisiones para cada letra (Aa Ae Aj Ao At)
- Considere usar cuál usa el TOC apropiado para el número de páginas en una página de categoría.
{{CatAutoTOC}}
Las subcategorías se dividen alfabéticamente junto con los artículos, lo que significa que la pantalla inicial de una categoría dividida puede no incluir todas sus subcategorías. Para que todas las subcategorías se muestren en cada pantalla, agregue un árbol de categorías al texto de la página de categorías, como se describe en la página de ayuda en Visualización de árboles de categorías y recuentos de páginas .
Las páginas de categorías pueden tener enlaces entre idiomas en la lista "Idiomas" en la barra lateral izquierda (en la máscara predeterminada), enlazando a las categorías correspondientes en Wikipedias de otros idiomas. Para editarlos en Wikidata , haga clic en el enlace "Editar enlaces" al final de la lista de idiomas.
Categorizar páginas
Cada página de Wikipedia debe pertenecer al menos a una categoría. (Sin embargo, no hay necesidad de categorizar las páginas de discusión , redirecciones o páginas de usuario , aunque pueden ubicarse en categorías donde sea apropiado). Además, cada página categorizada debe ubicarse en todas las categorías más específicas a las que lógicamente pertenece. . Esto significa que si una página pertenece a una subcategoría de C (o una subcategoría de una subcategoría de C, etc.), normalmente no se coloca directamente en C. Para conocer las excepciones a esta regla, consulte § Categorías epónimas y § No difundiendo las subcategorías a continuación.
Si bien normalmente debe quedar claro a partir del nombre de una categoría existente qué páginas debe contener, el texto de la página de la categoría a veces puede proporcionar información adicional sobre el contenido de la categoría potencial. Una forma de determinar si ya existen categorías adecuadas para una página en particular es verificar las categorías de páginas relacionadas con temas similares o relacionados. Otra forma es buscar nombres de categorías existentes como se describe aquí (parte superior de la página). Dado que todas las categorías forman parte de una jerarquía, no agregue categorías a las páginas como si fueran etiquetas .
Artículos
Aparte de ciertas excepciones (es decir, categorías epónimas y subcategorías que no se difunden , ver más abajo), un artículo debe clasificarse en la rama más específica posible del árbol de categorías, sin duplicación en las categorías principales por encima de ella. En otras palabras, los artículos rara vez deben colocarse tanto en una categoría determinada como en cualquiera de sus subcategorías o principales (super) categorías. Por ejemplo, el artículo "París" solo debe colocarse en "Categoría: Ciudades de Francia", no tanto en " Categoría: Ciudades de Francia " como en " Categoría: Lugares poblados de Francia".". Because the first category (cities) is in the second category (populated places), readers are already given the information that Paris is a populated place in France by it being a city in France.
Categorization of articles must be verifiable. It should be clear from verifiable information in the article why it was placed in each of its categories. Use the {{Uncited category}} template if you find an article in a category that is not shown by sources to be appropriate or if the article gives no clear indication for inclusion in a category.
Categorization must also maintain a neutral point of view. Categorizations appear on article pages without annotations or referencing to justify or explain their addition; editors should be conscious of the need to maintain a neutral point of view when creating categories or adding them to articles. Categorizations should generally be uncontroversial; if the category's topic is likely to spark controversy, then a list article (which can be annotated and referenced) is probably more appropriate. For example, a politician (not convicted of any crime) should not be added to a category of notable criminals.
A central concept used in categorizing articles is that of the defining characteristics of a subject of the article. A defining characteristic is one that reliable sources commonly and consistently define[1] the subject as having—such as nationality or notable profession (in the case of people), type of location or region (in the case of places), etc. For example, in Caravaggio, an Italian artist of the Baroque movement, Italian, artist, and Baroque may all be considered to be defining characteristics of the subject Caravaggio.
Particular considerations for categorizing articles:
- By convention, category declarations are placed at the end of the wikitext, but before any stub templates, which transclude their own categories.
- Eponymous categories should appear first. Beyond that, the order in which categories are placed on a page is not governed by any single rule (for example, it does not need to be alphabetical, although partially alphabetical ordering can sometimes be helpful). Normally the most essential, significant categories appear first.
- An article should never be left with a non-existent (redlinked) category on it. Either the category should be created, or else the link should be removed or changed to a category that does exist.
- Categorization should not be made by the type of an article. A biographical article about a specific person, for example, does not belong in Category:Biography (genre).
- Articles on fictional subjects should not be categorized in a manner that confuses them with real subjects. {{Category see also}} is useful for interlinking examples of real-world and fictional phenomena.
Eponymous categories
A category that covers exactly the same topic as an article is known as the eponymous category for that article (e.g. New York City and Category:New York City; Mekong and Category:Mekong River).
An eponymous category should have only the categories of its article that are relevant to the category's content. For example:
- Both New York City and Category:New York City fit well in Category:Cities in New York (state).
- The article New York City is in Category:Populated places established in 1624, but this category is not necessarily relevant to the content of Category:New York City, so it should not be used on the eponymous category.
Guidelines for articles with eponymous categories
- The article itself should be a member of the eponymous category and should be sorted with a space to appear at the start of the listing (see § Sort keys below).
- The article should be listed as the main article of the category using the {{cat main}} template.
- Articles with an eponymous category may be categorized in the broader categories that would be present if there were no eponymous category (e.g. the article France appears in both Category:France and Category:Western Europe, even though the latter category is the parent of the former category). Editors should decide by consensus which solution makes most sense for a category tree. There are three options:
- Keep both the eponymous category and the main article in the parent category. This is used in Category:Western Europe to allow that region's country articles to be navigated together.
- Keep just the child article. This is used in Category:British Islands, to prevent a loop.
- Keep just the eponymous category. This is used for Category:Farmworkers in Category:People by occupation. Such "X by Y" categories sometimes cover a limited navigational set, not a topic (see § Category tree organization below), thus there is no logical article content.
If eponymous categories are categorized separately from their articles, it will be helpful to make links between the category page containing the articles and the category page containing the eponymous categories. The template {{Related category}} can be used for this. An example of this set-up is the linked categories Category:American politicians and Category:Wikipedia categories named after American politicians.
Files/images
Category tags can be added to file/image pages of files that have been uploaded to Wikipedia. When categorized, files are not included in the count of articles in the category, but are displayed in a separate section with a thumbnail and the name for each. A category can mix articles and images, or a separate file/image category can be created. A file category is typically a subcategory of the general category about the same subject, and a subcategory of the wider category for files, Category:Wikipedia files. To categorize a new file when uploading, simply add the category tag to the upload summary.
Freely licensed files may also be uploaded to, and categorized on, Wikimedia Commons. This can be done instead of, or in addition to, uploading and categorizing on Wikipedia. Most freely licensed files will eventually be copied or moved from Wikipedia to Commons, with a mirror page remaining on Wikipedia. (For an example of one such mirror page, see here.) Categories should not be added to these Wikipedia mirror pages, because doing so creates a new Wikipedia page that is subject to speedy deletion. Exceptions to this principle are made for mirror pages of images that are nominated as featured pictures and for those that appear on the Wikipedia Main Page in the Did You Know? column.
Images that are used in Wikipedia that are non-free or fair use should not appear as thumbnail images in categories. To prevent the thumbnail preview of images from appearing in a category, __NOGALLERY__ should be added to the text of the category. In such cases, the file will still appear in the category, but the actual image preview will not.
Wikipedia administrative categories
A distinction is made between two types of categories:
- Administrative categories, intended for use by editors or by automated tools, based on features of the current state of articles, or used to categorize non-article pages.
- Content categories, intended as part of the encyclopedia, to help readers find articles, based on features of the subjects of those articles.
Administrative categories include stub categories (generally produced by stub templates), maintenance categories (often produced by tag templates such as {{cleanup}} and {{fact}}, and used for maintenance projects), WikiProject and assessment categories, and categories of pages in non-article namespaces.
Article pages should be kept out of administrative categories if possible. For example, the templates that generate WikiProject and assessment categories should be placed on talk pages, not on the articles themselves. If it is unavoidable that an administration category appears on article pages (usually because it is generated by a maintenance tag that is placed on articles), then in most cases it should be made a hidden category, as described in § Hiding categories below.
There are separate administrative categories for different kinds of non-article pages, such as template categories, disambiguation page categories, project page categories etc.
In maintenance categories and other administrative categories, pages may be included regardless of type. For example, in an error tracking category it makes sense to group templates separately, because addressing the errors there may require different skills compared to fixing an ordinary article. For sorting each namespace separately, see § Sort keys below.
User pages
User pages are not articles, and thus do not belong in content categories such as Living people or Biologists. They can however be placed in user categories – subcategories of Category:Wikipedians, such as Category:Wikipedian biologists – which assist collaboration between users.
Similarly, user subpages that are draft versions of articles should be kept out of content categories, but are permitted in non-content or project categories, like Category:User essays. If you copy an article from mainspace to userspace and it already contains categories, remove them or comment them out. Restore the categories when you move the draft back into article space. Two scripts are available to help with these tasks: User:DannyS712/Draft no cat and User:DannyS712/Draft re cat.
At Database reports/Polluted categories, a list of affected categories is maintained.
Draft pages
Drafts, no matter whether in the draft namespace or your userspace, are not articles, and thus do not belong in content categories such as Living people or Biologists. If you copy an article from mainspace to draftspace or your userspace and it already contains categories, then disable them: edit each by inserting a colon character to link to its category instead (e.g. change [[Category:Biologists]] to [[:Category:Biologists]]), or encompass them with the {{draft categories|1=[[Category:first category]][[Category:second category]] etc.}} template). Re-enable the categories when you move the draft back into article space.
Two scripts are available to help with these tasks: User:DannyS712/Draft no cat and User:DannyS712/Draft re cat.
Template categorization
Templates are not articles, and thus do not belong in content categories. It is however a recommendation to place them in template categories – subcategories of Category:Wikipedia templates – to assist when looking for templates of a certain type. For example, Template:Schubert string quartets is categorized under Category:String quartets by composer templates, which should be a subcategory of Category:Music navigational boxes (type) but Template:Schubert string quartets should not be categorized under Category:Franz Schubert or Category:String quartets (content).
It is usually desirable that pages using a template are not placed in the same categories as the template itself. To avoid this, the category for the template should be placed on the template's documentation page, normally within a <includeonly>{{Sandbox other||...}}</includeonly> block; if there is no documentation page, the category for the template may be placed on the template itself, within a <noinclude>...</noinclude> block. Where a <noinclude>...</noinclude> block is the last item in the template code, there should be no spaces or newlines between the last part of the template proper and the opening <noinclude> tag.
Categorization using templates
Many templates include category declarations in their transcludable text, for the purpose of placing the pages containing those templates into specific categories. This technique is very commonly used for populating certain kinds of administration categories, including stub categories and maintenance categories.
However, it is recommended that articles not be placed in ordinary content categories using templates in this way. There are many reasons for this: editors cannot see the category in the wikitext; removing or restructuring the category is made more difficult (partly because automated processes will not work); inappropriate articles and non-article pages may get added to the category; sort keys may be unavailable to be customised per category; and ordering of categories on the page is less controllable.
When templates are used to populate administration categories, ensure that the code cannot generate nonsensical or non-existent categories, particularly when the category name depends on a parameter. Also, see Category suppression for ways of keeping inappropriate pages out of template-generated categories.
Category declarations in templates often use {{PAGENAME}} as the sort key, because this overrides any DEFAULTSORT defined on the page.
Hiding categories
In cases where, for technical reasons, administration categories appear directly on articles rather than talk pages, they should be made into hidden categories, so that they are not displayed to readers. This rule does not apply to stub categories or "uncategorized article" categories – these types are not hidden.
To hide a category, add the template {{Wikipedia category|hidden=yes}} to the category page (the template uses the magic word __HIDDENCAT__). This also places the page in Category:Hidden categories.
A logged-in user may elect to view all hidden categories, by checking "Show hidden categories" on the "Appearance" tab of Preferences. Notice that "hidden" parent categories are never in fact hidden on category pages (although they are listed separately).
Hidden categories are listed at the bottom when previewing. All users of the desktop version can see hidden categories for a page by clicking "Page information" under "Tools" in the left pane, or by editing the whole page with the source editor.
Redirected categories
Do not create inter-category redirects. See Wikipedia:Categories for discussion#Redirecting categories for the policy, and Wikipedia:Redirect#Category redirects for the technical details.
Sort keys
Sort keys are sometimes needed to produce a correct ordering of member pages and subcategories on the category page. For the mechanics, see Sorting category pages on the help page.
Categories of people are usually sorted by last name rather than first name, so "surname, forename" sort keys are used (as in "Washington, George"). There are many other rules for sorting people's names; for more information, see WP:NAMESORT.
Other sort key considerations (in no particular order):
- In English Wikipedia, sort order merges (ignores) case and diacritics. For example, "Baé", "Båf", "BaG" would be sorted in that order.[2]
- The main article/s of a category, if existent, should get sorted with a space as key so that it/they appear at the very top of the category. Example:
[[Category:Example| ]]Those articles are typically homonymous or at least synonymous to their category. Furthermore, other general articles that are highly relevant to the category should be sorted with an asterisk as key so that they also appear at the top of a category but beneath the main article/s. Example:[[Category:Example|*]]Those articles are typically called "History of example", "Types of example", "List of example" or similar. - Leading articles—a, an, and the—are among the most common reasons for using sort keys, which are used to transfer the leading article to the end of the key, as in {{DEFAULTSORT:Lady, The}}. Please also apply these sort keys to deliberate misspellings of these words, e.g. "da" or "tha" for "the", as well as foreign language leading articles, such as "el" or "der" (but beware of non-article words that have the same spelling, e.g. that translate as "at" or "one"). However, leading articles in foreign-language-derived names which are no longer translated in English are not subject to this rule; e.g. the sort key for El Paso should be left as the default value (i.e. no {{DEFAULTSORT}} required).
- Landforms (and similar) that have noun prefixes such as Isle of Mull should have the noun sorted after as {{DEFAULTSORT:Mull, Isle of}}. However, this isn't usually done for settlements and administrative divisions; for example, while Isle of Wight uses {{DEFAULTSORT:Wight, Isle of}}, the categories for the county/district are sorted "Isle of Wight". Also for settlements such as Isle of Wight, Virginia the prefix isn't moved.
- Spell out abbreviations and characters used in place of words so that they can be found easily in categories. For example, the sort key for Mr. Bean should be {{DEFAULTSORT:Mister Bean}} and Dungeons & Dragons should be sorted {{DEFAULTSORT:Dungeons And Dragons}}. An exception is the times sign (×) as in "Men's 4 × 100 metre" relay; use the letter x in this case.
- Hyphens, apostrophes and periods/full stops are the only punctuation marks that should be kept in sort values. The only exception is the apostrophe in names beginning with O', which should be removed. For example, Eugene O'Neill is sorted {{DEFAULTSORT:Oneill, Eugene}}. All other punctuation marks should be removed. (Commas can be added when re-ordering words, as in the previous example.)
- Entries containing numbers sometimes need special sort keys to ensure proper numerical ordering. For example, IX comes before V in alphabetical order, so Pope John IX might have a sort key "John 9". To get the correct sort order zero padding may be required, thus the actual sort key for is "John 09" this ensures that Pope John IX sorts before Pope John X – if we ever get to the hundredth Pope John, we would need to use three digits "John 009". Also note that numbers which include separators (such as commas or periods) will only have the part of the number before the first separator considered by the sorting algorithm. So 10,000 Maniacs might have a sort key "10000 Maniacs". It is important to stick to the same system for all similar entries in a given category.
- Systematic sort keys are also used in other categories where the logical sort order is not alphabetical (for example, individual month articles in year categories such as Category:2004 use sort keys like "*2004-04" for April). Again, such systems must be used consistently within a category.
- In some categories, sort keys are used to exclude prefixes that are common to all or many of the entries, or are considered unimportant (such as "List of" or "The"). For example, in Category:2004 the page 2004 in film would have the sort key "Film", and in Category:2004 in Canada the page 2004 Canadian federal budget would have the sort key "Federal Budget".
- Use other sort keys beginning with a space (or an asterisk or a plus sign) for any "List of ..." and other pages that should appear after the key article and before the main alphabetical listings, including "Outline of" and "Index of" pages. The same technique is sometimes used to bring particular subcategories to the start of the list.
- Sort keys may be prefixed with Greek letters to place entries after the main alphabetical list. The following letters have special meaning by convention:
- "Σ" (capital sigma) is used to place stub categories at the end of subcategory lists. ("µ" (mu) was previously used, but the capital version "Μ" was confusing.)
- "β" (beta, displays as capital, "Β") is for barnstars.
- "Δ" (delta) is for documentation, where sorting by Latin D is undesirable.
- "ι" (iota, displays as "Ι") is for Wikipedia images.
- "ρ" (rho, displays as "Ρ") is for portals.
- "τ" (tau, displays as "Τ") is for templates. Keep in mind, template categories should not be added to content categories per WP:CAT#T.
- "υ" (upsilon, displays as "Υ") for user templates.
- "ω" (omega, displays as "Ω") is for WikiProjects.
- Similar to the handling of Latin letters, if the sort key is or begins with a lower case Greek letter, then the capital Greek letter will be displayed in headings on category pages. Items whose sort keys begin with lowercase letters will appear beneath corresponding capital letters. Several of these resemble Latin letters B, I, P etc., but they will sort after Z.
- Note: Not all of these types are suitable for inclusion in content categories. For one-type categories, such as template categories, Greek letter grouping is not useful.
- If a page is to be given the same sort key in all or several of its categories, the
{{DEFAULTSORT}}magic word should be used. Per WP:FOOTERS, this is placed just before the list of category declarations. Default sort keys are sometimes defined even where they do not seem necessary—when they are the same as the page name, for example—in order to prevent other editors or automated tools from trying to infer a different default.
Category tree organization
Categories are organized as overlapping "trees", formed by creating links between inter-related categories (in mathematics or computer science this structure is called a partially ordered set). Any category may contain (or "branch into") subcategories, and it is possible for a category to be a subcategory of more than one "parent" category. (A is said to be a parent category of B when B is a subcategory of A.) [3]
There is one top-level category, Category:Contents. All other categories are found below this. Hence every category apart from this top one must be a subcategory of at least one other category.
There are two main kinds of category:
- Topic categories are named after a topic (usually sharing a name with the Wikipedia article on that topic). For example, Category:France contains articles relating to the topic France.
- Set categories are named after a class (usually in the plural). For example, Category:Cities in France contains articles whose subjects are cities in France. A category may be explicitly labeled as such using the {{Set category}} template.
Sometimes, for convenience, the two types can be combined, to create a set-and-topic category (such as Category:Voivodeships of Poland, which contains articles about particular voivodeships as well as articles relating to voivodeships in general).
Subcategorization
If logical membership of one category implies logical membership of a second (an is-a relationship), then the first category should be made a subcategory (directly or indirectly) of the second. For example, Cities in France is a subcategory of Populated places in France, which in turn is a subcategory of Geography of France.
Many subcategories have two or more parent categories. For example, Category:British writers should be in both Category:Writers by nationality and Category:British people by occupation. When making one category a subcategory of another, ensure that the members of the subcategory really can be expected (with possibly a few exceptions) to belong to the parent also. Category chains formed by parent–child relationships should never form closed loops;[4] that is, no category should be contained as a subcategory of one of its own subcategories.[5] If two categories are closely related but are not in a subset relation, then links between them can be included in the text of the category pages.
Except for non-diffusing subcategories (see below), pages for sub-categories should be categorised under the most specific parent categories possible.
Sometimes proper subcategorization requires the creation of new categories.
Note also that as stub templates are for maintenance purposes, not user browsing (see § Wikipedia administrative categories above), they do not count as categorization for the purposes of Wikipedia's categorization policies. An article which has a "stubs" category on it must still be filed in the most appropriate content categories, even if one of them is a direct parent of the stubs category in question.
Diffusing large categories
Although there is no limit on the size of categories, a large category will often be broken down ("diffused") into smaller, more specific subcategories. For example, Category:Rivers of Europe is broken down by country into the subcategories Rivers of Albania, Rivers of Andorra, etc.
A category may be diffused using several coexisting schemes; for example, Category:Albums is broken down by artist, by date, by genre etc. Metacategories may be created as ways of organizing schemes of subcategories. For example, the subcategories called "Artistname albums" are not placed directly into Category:Albums, but into the metacategory Category:Albums by artist, which itself appears in Category:Albums. (See Category:Categories by parameter)
It is possible for a category to be only partially diffused—some members are placed in subcategories, while others remain in the main category.
Information about how a category is diffused may be given on the category page. Categories which are intended to be fully broken down into subcategories can be marked with the {{category diffuse}} template, which indicates that any pages which editors might add to the main category should be moved to the appropriate subcategories when sufficient information is available. (If the proper subcategory for an article does not exist yet, either create the subcategory or leave the article in the parent category for the time being.)
To suggest that a category is so large that it ought to be diffused into subcategories, you can add the {{overpopulated category}} template to the category page.
Non-diffusing subcategories
Not all subcategories serve the "diffusion" function described above; some are simply subsets which have some special characteristic of interest, such as Best Actor Academy Award winners as a subcategory of Film actors or Musical films as a subcategory of Musicals. These are called non-diffusing subcategories. They provide an exception to the general rule that pages are not placed in both a category and its subcategory: there is no need to take pages out of the parent category purely because of their membership of a non-diffusing subcategory. (Of course, if the pages also belong to other subcategories that do cause diffusion, then they will not appear in the parent category directly.)
Non-diffusing subcategories should be identified with a template on the category page:
- The {{Non-diffusing subcategory}} templates should be used for sub-categories that are non-diffusing, like Category:American novelists of Asian descent.
- The {{All included}} can be used for categories where all child articles of a certain type are in the parent, like Category:Presidents of the United States or Category:Mountains of Switzerland.
Subcategories defined by gender, ethnicity, religion, and sexuality should almost always be non-diffusing subcategories. The Wikipedia:Categorization/Ethnicity, gender, religion and sexuality categorization guideline outlines the rules on these categories in more detail.
Note that some categories can be non-diffusing on some parents, and diffusing on others. For example, Category:British women novelists is a non-diffusing sub-category of Category:British novelists, but it is a diffusing subcategory of Category:Women novelists by nationality.
Category cleanup templates
- Article with insufficient categories
- {{Improve categories}} template indicates that the article needs additional or more specific categories. It is recommended that this template be placed at the bottom of the page, where readers will look for the categories.
- Article with too many categories
- Use {{Recategorize}} template when there are too many categories. Put this template on the top of articles.
- Incorrect category
- The {{Check category}} template can be used to flag a page that may be in the wrong category or which you believe may need adding to additional categories. It will add the page to Category:Category needs checking.
- Category unknown
- If you're not sure where to categorise a particular page, add the {{uncategorized}} template to it, and other editors (such as those monitoring Wikipedia:WikiProject Categories/uncategorized) will help find appropriate categories for it.
See also
- Wikipedia:Categorization dos and don'ts (information page summarizing key points of this guideline)
- Wikipedia:Category suppression
- Wikipedia:WikiProject Categories
- m:Association of Categorist Wikipedians
- m:Help:Sorting
- Category:Wikipedia essays about categorization
- Wikipedia:FAQ/Categorization
- Help:Gadget-Cat-a-lot, script for moving subcategories between categories
- Wikipedia:Maintenance
For browsing
- Wikipedia:PetScan (formerly CatScan)
- Wikipedia:Classification (category tree jumping)
- Wikipedia:Category intersection (ability to find articles that are in more than one category)
- Special:Categories (lists all existing categories alphabetically)
- Special:CategoryTree
- Category:Wikipedia categories
For maintenance
- Special:Mostlinkedcategories
- Special:Uncategorizedimages
- Special:Uncategorizedpages
- Special:Unusedcategories
- Special:Wantedcategories
- Wikipedia:Category combinatorics
- Wikipedia:Database reports#Categories
- Template:Category link with count
Notes
- ^ in prose, as opposed to a tabular or list form
- ^ In 2016, English Wikipedia's category collation was changed to "uca-default", which is based on the Unicode collation algorithm (UCA). The most noticeable difference is that UCA groups characters with diacritics with their non-diacritic versions. See Wikipedia talk:Categorization/Archive 16 § OK to switch English Wikipedia's category collation to uca-default? and Wikipedia:Village pump (technical)/Archive 149 § Sorting in categories unreliable for a few days.
- ^ Mathematically speaking, this means that the system approximates a directed acyclic graph.
- ^ This condition can be formulated in terms of graph theory as follows: the directed graph that has the categories as vertices and the parent-child relationships as edges should be acyclic.
- ^ There is an exception to this for maintenance purposes. For example, Category:Hidden categories is a direct subcategory of itself and of Category:Wikipedia extended-confirmed-protected pages and Category:Container categories, each of which is a direct subcategory of Category:Hidden categories.
