Misplaced Pages

:Categorization: Difference between revisions - Misplaced Pages

Article snapshot taken from Wikipedia with creative commons attribution-sharealike license. Give it a read and then ask your questions in the chat. We can research this topic together.
Browse history interactively← Previous editContent deleted Content addedVisualWikitext
Revision as of 00:53, 27 September 2005 view sourceRick Block (talk | contribs)Administrators31,124 edits replace naming conventions with reference to Misplaced Pages:Naming conventions (categories)← Previous edit Latest revision as of 04:51, 15 December 2024 view source Jc37 (talk | contribs)Administrators48,863 editsm typo 
Line 1: Line 1:
{{short description|Guidance on the proper use of the categorization function in Misplaced Pages}}
{{shortcut|]}}
<noinclude>{{pp-semi-indef}}{{pp-move-indef}}</noinclude>
{{guideline}}
{{Hatnote|"WP:CATEGORY" and "WP:CAT" redirect here. You may be looking for ] (a list of top-level categories), ], ], ], or even ]. For the category system itself, see ].}}
{{clearright}}
{{Redirect|WP:CG|the internal project on computer-generated imagery|Misplaced Pages:WikiProject Computer graphics}}
{{Style}}
{{Subcat guideline|editing guideline|Categorization|WP:CAT|WP:CATEGORY|WP:MOSCAT}}
This article provides guidelines on creating and organizing categories.
{{Guideline list}}
{{For|information on the mechanics of the function, category syntax, etc.|Help:Category}}
{{For|quick answers|Misplaced Pages:FAQ/Categorization}}


This page contains ] on the proper use of the '''categorization''' function in Misplaced Pages. The '''central goal''' of the category system is to provide ] to pages in Misplaced Pages within a hierarchy of ''categories''. Using essential, '']'' characteristics of a topic, readers can browse and quickly find sets of pages on topics that are defined by those characteristics.
For a quick introduction to categories, see ]. For everything you ever wanted to know about categories, see ].


For proposals to delete, merge, or rename categories, follow the instructions at ]. Please use it before undertaking any complicated re-categorization of existing categories or mass creation of new categories.
==When to use categories==


==Categorizing pages==
Every page in the article namespace should have at least one category. Categories should be on major topics that are likely to be useful to someone reading the article.
]]]
{{details|Help:Category}}
{{see also|Misplaced Pages:Categorization dos and don'ts|Misplaced Pages:Categorizing redirects}}
Every ] should belong to at least one category, except for ], ], and ], which may optionally be placed in categories where appropriate.


{{anchor|CATSPECIFIC|PARENTCAT|GRANDPARENT}}{{shortcut|WP:CATSPECIFIC|WP:PARENTCAT|WP:GRANDPARENT}}Each categorized page should be placed in all of the {{em|most specific}} categories to which it logically belongs. And pages should not normally be placed in both a given category and any of its sub- or parent (super-) categories. For exceptions to this, see ] and ].
:'''Article:''' ]
:'''Useful category:''' ]
:'''Not useful:''' ''Category:Musicians whose first name starts with M''


This means that if a page belongs to a ] of C (or a subcategory of a subcategory of C, and so on) then it is ''not'' normally placed directly into C.
Questions to ask to know if a category is the appropriate tool:
* For example, the article "Paris" need only be placed in ], ''not'' also in ]. 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.


Since all categories form part of a ], ''do not add categories to pages as if they are ]''.
*Is it possible to write a few paragraphs or more on the subject of a category, explaining it?
*If you go to the article from the category, will it be obvious why it's there? Is the category subject prominently discussed in the article?


{{anchor|CREATECAT}}
If the answer to either of these questions is no, then a category is probably inappropriate.
== Creating category pages ==
{{shortcut|WP:CREATECAT}}
{{anchor|BEFORECAT}}
===Before creating a new category===
{{main|Misplaced Pages:Categories, lists, and navigation templates|Misplaced Pages:Overcategorization}}
{{see also|Help:Sortable tables}}
{{shortcut|WP:BEFORECAT}}


Categories are not the only means of enabling users to browse sets of related pages. And categories have ], including that categories only show ''the page name'' of each page being categorized, therefore:
An article will often be in several categories. Restraint should be used, however &mdash; categories become less effective the more there are on a given article.


*While the ] may provide broader information, individual category members cannot be annotated with descriptions or comments, so they give no context or elaboration for any specific entry.
An article should not be in both a category and its subcategory, for example ] is in ], so should not also be in ]. An article with the same name as a category should usually belong only to that category, for instance, ] belongs only in ].
*There is no provision for referencing any specific entry, to ] a page meets a category's criteria of inclusion.


So, consider whether a ] would be more appropriate for such a grouping of pages. Lists would also be more useful where it is important to see dates, for example, a ]. And can provide options for sorting the entries.
Categories appear without annotations, so be careful of ] when creating or filling categories. Unless it is self-evident and uncontroversial that something belongs in a category, it should not be put into a category.


Also, consider whether the category might be considered category clutter. Please see ], for more information on this.
Exceptions to the above rules are categories such as ] which are intended to aid the function of Misplaced Pages editing.


=== Choosing a name for the category ===
For alternative methods of grouping articles, and the circumstances in which they should be used, see ].
{{Main|Misplaced Pages:Category names}}
{{see also|#Naming conventions}}
A good category name is accurate and ''']''', and, as much as possible, defines the category's inclusion criteria in the name itself.


''Important:'' Moving non-conventionally categorized pages to another category name (see {{tl|Category redirect}}) imposes an additional overhead – an edit for ''every'' categorized page and subcategory.
For articles without any stable category, {{tl|catneeded}} tag can be used to bring attention (although ] exists).


So, when choosing a name for the category, please be sure a similar category does not exist. Before creating a category, try to find it under a similar name. You can search existing category names as described ] (top of page). Another way to determine if suitable categories already exist for a particular page is to check the categories of pages concerning similar or related topics.
===Categories vs. Lists vs. Info boxes===
*For example: You might want to add a subcategory for people to ]. By starting at ], you will discover that Mexicans are placed in ].


''Note:'' ] (categories whose name and topic is the same as an article, such as a category named after a person) should only be created if enough directly related articles exist.
See, ].


===Categories applied to articles on people=== === Creating the category ===
After you have determined an appropriate category name for the category, next try to find a suitable place for the new category. (For example, categories of people should be in the ].) Please see ] for more information on this.


Once you have determined where to categorize this new category, you should be ready to create the new category.
A separate wikipedia page ] was created to help you in designing, applying and checking categories that are used for articles on people.


To create a category:
==Categories do not form a tree==
# Add a page to the intended category. Do this by editing that page, and add the name of the new category: (e.g.:&nbsp;{{code|]}}&nbsp;)
#* {{Shortcut|MOS:CATORDER}}By convention, categories are placed at the end of the wikitext, but before any ] templates, which transclude their own categories.
#* {{Anchor|CATORDER}}] 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. <!-- There is currently no ] about the order in which categories should be placed at the bottom of an article. -->
# Save your edit. The as-yet-undefined category name will now appear as a ] in the category list at the bottom of the page.
#* {{Anchor|CATREDLINK}}{{Shortcut|WP:CATREDLINK}} A page should never be left with a non-existent (]) category on it. Either the category should be created, or else the link should be removed or changed to a category that does exist.
# Next, click on that red link, which brings you to the new category page to create.
# Finally, at the bottom of the category page, simply add the parent category (e.g.:&nbsp;{{code|]}}&nbsp;), which should usually be a ] of the subcategory. This will add the new category into the appropriate parent category.
{{n.b.}} If something goes wrong, double check to see if you followed the steps properly and check if the wikitext is correct. For example, if the category fails to list in the parent category, the wikitext should be <nowiki>]</nowiki>, not <nowiki>]</nowiki>.


{{anchor|CATDESC}}
Each Misplaced Pages article can appear in more than one category, and each category can appear in more than one parent category. Multiple categorization schemes co-exist simultaneously. In other words, categories do not form a strict hierarchy or ], but a more general ] (or close to it, see below).
=== Category description ===
{{shortcut|WP:CATDESC}}
While it should typically be clear from the name of an existing category which pages it should contain, sometimes, a common-sense guess based on the name of the category isn't enough to figure out whether a page should be listed in the category. So, rather than leave the text of a category page empty (containing only parent category declarations), adding a ] which describes the topic, can help with that.


However, only linking to a Misplaced Pages article explaining the title is often not sufficient as a description for a category. It can be helpful – to both readers and editors – to include a clear description of the category, indicating what pages it should contain, how they should be subcategorized, and so on, and linking to one or more pages as background information.
Nevertheless, parts of the category graph will be tree-like, and it may be convenient to think of parts of the category graph as being like multiple overlapping trees.


In such cases, the desired contents of the category should be described on the category page, similar to how the ] are described in a stand-alone list. The category description should make direct statements about the criteria by which pages should be selected for inclusion in (or exclusion from) the category. This description, not the category's name, defines the proper content of the category. Do not leave future editors to guess about what or who should be included from the title of the category. Even if the selection criteria might seem obvious to you, an explicit standard is helpful to others, especially if they are less familiar with the subject.
==Cycles should usually be avoided==


The description can also contain links to other Misplaced Pages pages, in particular to other related categories which do not appear directly as subcategories or parent categories, and to relevant categories at ], such as ]. Another technique that can be used is described at ]. Like ] pages, category pages should not contain either citations to ] or ].
Although the MediaWiki software does not prevent ] (loops), these should usually be avoided.


Various templates have been developed to make it easier to produce category descriptions; see ]. There are hatnote templates including {{tl|Category main article}} and {{tl|Category see also}}; others are listed at ].
==Guidelines for assignment of categories==
<!--:If this section stabilizes, it should probably be moved into the User's Guide. -- ] 08:06, 13 Jun 2004 (UTC)
::Maybe with a major rewrite. It is all but useless right now, giving no basic information on How to create categories/subcategories - ] 21:57, 5 Jul 2004 (UTC) -->


=== Additional considerations ===
===How to create categories===
Categories may have hundreds of members, displayed over many pages, with, at most, only 200 category entries on a single category page. To make navigating large categories easier, a table of contents can be used on the category page. The following templates are some of the ways of doing this:
* {{Tl|Category TOC}} – adds a complete table of contents (Top, 0–9, A–Z)
* {{Tl|Large category TOC}} – adds a complete table of contents with five subdivisions for each letter (Aa Ae Aj Ao At)
* Consider using <code>{{tl|CatAutoTOC}}</code> which uses the appropriate TOC for the number of pages on a category page.


Likewise, a maximum of 200 subcategories are displayed at a time, so some subcategories may not be immediately visible. To display all subcategories at once, add a category tree to the text of the category page, as described at {{Section link|Help:Category#Displaying category trees and page counts}}.
Creating a category is as simple as adding a soft link to the appropriate article in the Category: namespace; for instance, to add ] to the "fluffy creatures" category, you would edit the article and enter <tt><nowiki>]</nowiki></tt> at the bottom, but ''before'' ]. Although the link will not appear in the article text, a page called <tt>Category:Fluffy creatures</tt> will automatically list alphabetically all articles that contain the <tt><nowiki>]</nowiki></tt> link. The appeal of categories is that unlike lists, they update themselves automatically, and that one can use them to quickly find related articles. However, categories are not a substitute for ]s, and you will find that many articles belong to both lists and categories. You may see some inconsistencies when first creating the category: it may alternate between appearing empty and appearing with your first additions. It will probably correct itself in a few minutes.


Category pages can have ] in the "Languages" list in the left sidebar (in the default skin), linking to corresponding categories in other language Wikipedias. To edit these on ], click on the "Edit links" link at the end of the languages list.
Note that, although "uncreated" categories ''will'' correctly list articles that have been assigned to them, the category page itself does not exist until it is manually created. The easiest way to create the category page is to follow the edit link from an article and add a parent category and a category description as explained below.


{{anchor|ARTICLES|Articles}}
===Creating subcategories===
== Categorization of articles ==
Create subcategory pages by putting the name of the parent category on a category page that you would like to be the subcategory. Child categories (subcategories) are created by putting <nowiki>]</nowiki> '''on the lower-level category pages'''. For example, on a (sub)category page called ''category:Roses'' you put <nowiki>]</nowiki>, Roses becomes a subcategory of Flowers.
{{anchor|NC}}
=== Naming conventions ===
{{Main|Misplaced Pages:Category names}}
{{Transcluded section|Misplaced Pages:Categorization/Naming}}
{{Misplaced Pages:Categorization/Naming}}


=== Categorizing articles===
When adding an article to a category, or creating categories, one should be careful to use the correct categories and subcategories. Horizontal categorization, directly below, refers to placing an article in the correct category while vertical categorization refers to placing an article in the correct ''sub''category.
{{For|category types to avoid|Misplaced Pages:Overcategorization}}


In general, categories of articles must be:
When assigning an article into categories, try to be thorough in a
"horizontal" sense. The topic may be associated with a geographic
area, a historical period, an academic subfield, a certain type of
thing (like a food or an ornament), and/or a special interest topic
(like Roman Empire or LBGT). You might need to poke around the
category hierarchy a bit to find the right place. Try searching for
articles similar to the article you are categorizing to get ideas or
to find the most appropriate place. (For instance, '1990' is more correctly in 'Category:Years' rather than 'Category:Places'.)


*{{Anchor|V|Verifiable|Verifiability|CATV}}{{Shortcut|WP:CATV|WP:CAT#V}} ''''']''''': It should be clear from verifiable information in the article why it was placed in each of its categories. Use the {{tl|Unreferenced 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.
In the "vertical" dimension, you should probably be more frugal. A
good general rule is that articles should be placed in the most
specific categories they reasonably fit in. For example,
] should not be
listed directly under People, but Queens of England might be a good
place for her. We know that all Queens of England qualify as Famous
Britons and as Royalty, and all of those folks qualify as People. But
sometimes there's a good reason to assign an article to two
categories, one of which is a direct or indirect subcategory of
another. For a well-argued case study, see ].


*{{Anchor|POV|NPOV|CATPOV|POVCAT}}{{anchor|Neutral|N}}{{Shortcut|WP:CATPOV|WP:POVCAT|WP:CAT#N}} ''''']''''': 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 ] (which can be annotated and referenced) is probably more appropriate.
Whatever categories you add, make sure they do not implicitly violate
*: For example, a politician (not convicted of any crime) should not be added to a category of notable criminals.
the neutral point of view policy. If the nature of something is in
dispute (like whether or not it's fictional or scientific or whatever),
you may want to avoid labelling it or mark the categorization as
disputed. Most categorizations are pretty straightforward, though.


*{{Anchor|Defining characteristics|Defining|D|DEF}}{{Shortcut|WP:CATDEF|WP:CAT#D}} ''''']''''': <section begin=DefiningDef /><section begin=DefiningFull />Defining characteristics of an article's topic are central to categorizing the article. A defining characteristic is one that ] ''commonly'' and ''consistently'' refer to<ref>in declarative statements, rather than table or list form</ref> in describing the topic, such as the nationality of a person or the geographic location of a place.<section end=DefiningDef />
===Making groups of subcategories===
*:For example, ''Italian'' and ''artist'' are defining characteristics of ], because virtually all reliable sources on the topic mention them, so that article is included in categories such as ].<section end=DefiningFull />
Categories can only list 200 entries at a time. When there are more than 200 entries, only the first 200 will be displayed. To make it easy to navigate, add a TOC (table of contents). TOCs are added by typing:
:'''''<nowiki>{{CategoryTOC}}</nowiki>''''' - which adds a complete TOC (Top, 0 - 9, A-Z)
:'''''<nowiki>{{CatAZ}}</nowiki>''''' - which adds a TOC without numbers. This is for categories with members that only start with letters.


:Be sure to include categories for all defining characteristics. For non-defining characteristics, editors should use their judgment to choose which additional categories (if any) to include.
When a given category gets crowded, also consider making several subcategories. Group similar articles together in a meaningful and useful way that will make it easy for readers to navigate later. Remember that several subcategorization schemes can coexist (for example, if ] gets too big, you don't have to choose between subdividing it by function or subdividing it by platform, you can simultaneously subdivide it in both ways).
::For example, ] is included in the non-defining category of ].


==== Categorizing articles about people ====
A set of related categories often forms a hierarchy or a nexus. This can take several different forms, all of which are welcome and encouraged:
{{main|Misplaced Pages:Categorizing articles about people}}
{{see also|Category:People}}
{{shortcut|WP:SEPARATE}}<section begin=CAAPEOPLE />
*For ], categorize by characteristics of the person the article is about, <em>not</em> characteristics of the <em>article</em>: e.g., do not add <code><nowiki>]</nowiki></code> to an article. ] of ] may legitimately contain articles about biographical <em>films</em> or biographical <em>books</em>, but should not contain articles about individual people. The <em>article</em> is a biography; the topic of the article{{snd}}the <em>person</em>{{snd}}is not.
*{{Anchor|SEPARATE}} Keep articles about people separate. Categories with a title indicating that the contents are people, should normally only contain biographical articles and lists of people, and perhaps a non-biographical main article, though this can also be added at the top of the category. This is for clarity and ease of use, and to preserve the integrity of ].<section end=CAAPEOPLE />


==== Categorizing articles about works ====
* A taxonomic grouping. For example, ] is part of a geographical hierarchy. ] catalogs divisions between fields of study.
{{see also|Category:Creative works|Misplaced Pages:Category names#Works of art categories by subject}}
*Individual ] should not be included in an ] but should instead be in a subcategory such as ].
*{{Anchor|CATFICTION}}{{Shortcut|WP:CATFICTION}} Articles on fictional subjects should not be categorized in a manner that confuses them with real subjects. {{tl|Category see also}} is useful for interlinking examples of real-world and fictional phenomena.


==== Categorizing list pages ====
* A functional grouping. Examples: ], ], and ]. These bring together articles and subcategories from different fields or taxonomies (history, war, culture, people, companies, industries, technologies) that have an interesting common thread.
{{see also|Category:Lists}}
If there are more than a few ] in a particular subject area, it may be appropriate to create a specific subcategory that contains only the list pages and no other types.
* For example, ] contains the subcategory "]", which in turn contains the list pages "]", and "]".
When placing list pages in such a category, use a ] to adjust the page title to exclude the starting words "List of", or all lists would appear under "L".
* For example, when adding List of Soviet Republics to the category, using <code><nowiki>]</nowiki></code> and will make it be sorted in the S section.


{{anchor|EPON|OCEPON|EPONYMOUS|Eponymous category}}
* Hybrid forms. For example, ] is both part of the taxonomy of ] and a cross-reference point for lots of things that have little in common except that they have something to do with art.
==== Eponymous categories ====
{{Shortcut|WP:EPON|WP:OCEPON|WP:EPONYMOUS}}
{{see also|Category:Eponymous categories|Category:Misplaced Pages categories named after people}}
{{for|the overuse of the word "eponymous" on Misplaced Pages|WP:TITULAR}}
A category that covers exactly the same topic as an article is known as the '''eponymous category''' for that article (e.g. ] and ]; ] and ]; ] and ]).


Eponymous categories should not be created unless enough directly related articles or subcategories exist. However, this should not be done simply to reduce the number of categories displayed in an article.
===Category membership and creation===
When writing the description for a category, give it a parent category. In fact, you should try to give it at least two parent categories. For example, ] should be in both ] and ]. A few categories do only merely subdivide their parent category, but unless the parent category has many potential articles under it, or many potential subdivisions, if you can't think of a second parent category, it might be a better idea to fold your smaller category into the parent.


An eponymous category should have only the categories of its article that are relevant to the category's content. For example:
===Misplaced Pages namespace===
*Both ] and ] fit well in ].
*The article ] is in ], but this category is not necessarily relevant to the content of ], so it should not be used on the eponymous category.


{{anchor|CATMAIN|MAIN}}
Categories relating to the ] should be added only to the ] of articles. For example, tags suggesting the article is ], would be placed on the talk page as they are relevant to editors, not an aid to browsing in the way ordinary categories are. Please use <nowiki>{{wpcat}}</nowiki> on the Category description page to show that it is a Misplaced Pages-namespace category.
===== Articles with eponymous categories =====
{{Redirect|WP:CATMAIN|the template|Template:Category main article}}
{{Shortcut|WP:CATMAIN}}
*The article itself should be a member of the eponymous category. It should be sorted with a space, so that it appears at the start of the category listing (see ] below).
*The article should be listed as the main article of the category using the {{tl|Category main article}} 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 ] appears in both ] and ], 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 ] to allow that region's country articles to be navigated together.
# Keep just the child article. This is used in ], to prevent a loop.
# Keep just the eponymous category. This is used for ] in ]. Such "''X'' by ''Y''" categories sometimes cover a limited navigational set, not a topic (see ] 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 {{Tl|Related category}} can be used for this. An example of this set-up is the linked categories ] and ].
===User namespace===
Categories relating to the User namespace should be added only to Misplaced Pages-specific categories. Users should ''not'' add their user pages to article namespace categories such as ] or other subcategories, ] etc, which are reserved for pages in the article namespace. However, it is appropriate to add a user page to ''Misplaced Pages-specific categories'' such as ] or other similar subcategories such as ]. (See also ] for guidelines on category "pollution").


{{anchor|DRAFTNOCAT}}
If you copy an article to your user namespace (for example, as a temporary draft or in response to an edit war) you should decategorize it.
== Categorizing draft pages ==
{{shortcut|WP:DRAFTNOCAT}}
{{Further|Misplaced Pages:Drafts#Preparing drafts}}


Drafts, no matter whether in the ] or ], are not articles, and thus do not belong in content categories such as ] or ]. If you copy an article from mainspace to draftspace or your userspace and it already contains categories, then disable those categories. This can be done either by inserting a colon character to ] (e.g. change <code><nowiki>]</nowiki></code> to <code><nowiki>]</nowiki></code>), or by wrapping them in {{tl|Draft categories}} (e.g.<code><nowiki>{{draft categories|1=] ]}}</nowiki></code> etc.). After you move the draft into article space, remove the leading colons to re-enable the categories. If using the draft categories template, the categories will automatically work as normal in mainspace, but the template should be removed. The same system may be used in a new draft to list the categories it may have when moved to mainspace.
===Image namespace===
See ].


Two scripts are available to help with these tasks: ] and ].
==Category naming==
Categories follow the same general naming conventions as articles, for example do not capitalise regular nouns. For specific conventions related to categories, see ].


Drafts may be placed in the appropriate subcategories of ].
==Categories requirements and usage==
===User browsing===
Categories (along with other features, like cross-references) should help users find the information they are looking for as quickly as possible, even if they don't know that it exists or what it's called.


== Categorizing project pages ==
===Links to categories===
{{anchor|Non-article and maintenance categories|Maintenance categories|Contents category|Content category|Administrative category|PROJCATS}}
You can create a link to a category page without adding the page to that category by using a colon before the word Category. Example: <tt><nowiki>]</nowiki></tt> appears as ].
===Misplaced Pages administrative categories ===
{{Shortcut|WP:PROJCATS}}
{{see|Misplaced Pages:Administration#Data structure and development}}
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 ] templates), '''maintenance categories''' (often produced by tag templates such as {{tl|cleanup}} and {{tl|fact}}, and used for ] projects), '''] and ]''', and '''categories of pages in non-article ]'''.

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 ] below.

There are separate administrative categories for different kinds of non-article pages, such as ] categories, ], ] 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 ] below.

{{anchor|FILECAT|Images|Files/images}}
=== Files ===
{{shortcut|WP:FILECAT}}
{{see|Misplaced Pages:Manual of Style/Images#Image description pages}}
Category tags should be added to ] pages of files that have been uploaded to Misplaced Pages. 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, ]. To categorize a new file when uploading, simply add the category tag to the ].

Freely licensed files should be uploaded to, and categorized on, ], instead of uploading and categorizing on Misplaced Pages. Existing freely licensed files should usually be moved from Misplaced Pages to Commons, with a mirror page automatically remaining on Misplaced Pages. (For an example of one such mirror page, see ].) Categories should not be added to these Misplaced Pages mirror pages, because doing so creates a new Misplaced Pages page that is subject to ]. Exceptions to this principle are made for mirror pages of images that are nominated as ] and for those that appear on the Misplaced Pages ] in the ] column.

Images that are used in Misplaced Pages that are ] should not appear as thumbnail images in categories. To prevent the thumbnail preview of images from appearing in a category, <nowiki>__NOGALLERY__</nowiki> 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.

{{anchor|TEMPLATE|TEMPLATES|TEMP|T}}
=== Templates===
{{shortcut|WP:CAT#T}}
{{See also|Template:Documentation}}
] are not articles, and thus do not belong in ''content categories''. It is however a recommendation to place them in '''template categories''' – subcategories of ] – to assist when looking for templates of a certain type. For example, ] is categorized under ], which should be a subcategory of ] (type) but ] should ''not'' be categorized under ] or ] (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 {{tag|includeonly|content={{tlp|Sandbox other||...}}}} block; if there is no documentation page, the category for the template may be placed on the template itself, within a {{tag|noinclude}} block. When a {{tag|noinclude}} block is the last item in the template code, there should be no spaces or new lines between the last part of the template proper and the opening {{tag|noinclude|o}} tag.

{{anchor|User namespace|Categorizing user pages|USERNOCAT}}
===User pages ===
{{shortcut|WP:USERNOCAT}}
{{Further|Misplaced Pages:User categories|Misplaced Pages:User pages#Categories, templates that add categories, and redirects}}

] are not articles, and thus do not belong in ''content categories'' such as ] or ]. They can however be placed in '''user categories''' – subcategories of ], such as ] – which assist collaboration between users.

Similarly, ] that are draft versions of articles should be kept out of content categories, but are permitted in non-content or project categories, like ]. If you copy an article from mainspace to userspace and it already contains categories, wrap them inside {{tl|Draft categories}}, remove them, or ]. Restore the categories when you move the draft back into article space. Two scripts are available to help with these tasks: ] and ].

Also, do not ] articles into your user pages: this will result in the user page being included in all the article's categories.

At ], a list of affected categories is maintained.

{{anchor|TEMPLATECAT|TCAT}}
==Categorization using templates==
{{shortcut|WP:TEMPLATECAT|WP:TCAT}}

Many ] include category declarations in their transcludable text, for the purpose of ]. This technique is very commonly used for populating certain kinds of administration categories, including stub categories and maintenance categories. See ] for an example that only adds a category by manufacturer if it exists, and otherwise uses a hidden category.

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; ] 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 ] for ways of keeping inappropriate pages out of template-generated categories.

Category declarations in templates often use <code><nowiki>{{PAGENAME}}</nowiki></code> as the sort key, because this overrides any DEFAULTSORT defined on the page.

{{anchor|HIDDENCAT}}
===Hiding categories===
{{Shortcut|WP:HIDDENCAT}}
{{see also|mw:Help:Categories#Hidden 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 ] categories or "uncategorized article" categories – these types are ''not'' hidden.

To hide a category, add the template {{tlx|Misplaced Pages category|<nowiki>hidden=yes</nowiki>}} to the category page (the template uses the ] <code><nowiki>__HIDDENCAT__</nowiki></code>). This also places the page in ].

A logged-in user may elect to view all hidden categories, by checking "Show hidden categories" on the "Appearance" tab of ]. 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=== ===Redirected categories===
Do not create inter-category redirects. See {{section link|Misplaced Pages:Categories for discussion|Redirecting categories}} for the policy, and {{section link|Misplaced Pages:Redirect|Category redirects}} for the technical details.
Although it is possible to attempt to redirect categories by adding a line such as <tt><nowiki>#REDIRECT ]</nowiki></tt> to a category, it is not generally recommended because of limitations in the mediawiki software. Categories "redirected" in this way do not prevent the addition of articles to the redirected category. Articles added to the "redirected" category do not show up as in the target category.
Until these issues are addressed (in future versions of the software), '''#REDIRECT''' should not be added to category pages.


{{anchor|TREE}}
===Category sorting===
==Category tree organization==
Contrary to some expectations, text after a pipe ("<tt>|</tt>") in a category link is not used in place of the category text. Rather, this text is used as the sort key on the category page itself. However, again contrary to expectations, that sort text is not displayed.
{{Shortcut|WP:CAT#TREE}}
]


Categories are organized as overlapping "]", formed by creating links between inter-related categories (in mathematics or computer science this structure is called <!---wp's cat.s don't have unique joins or meets---a lattice or---> a ]). 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.) <ref>Mathematically speaking, this means that the system approximates a ].</ref>
For example, the ] uses this property to sort secondary interstates by their primary. That is, the category link in the article for ] is <tt><nowiki>]</nowiki></tt>. This causes "Interstate 190 (Illinois)" to be listed right after "Interstate 189" and right before "Interstate 290 (Massachusetts)" under the heading "9" in the category page.


There is one top-level category, ]. 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.
This feature is very useful for categories in which:
* the entries are people, in which case sorting by last name is preferable (example: ]).
* variations in the naming of entries causes inconsistent sorting (example: ], ], but ] in ]).
* the logical sort order is not alphabetical (example: individual month articles in year categories such as ], using e.g. the sort key "*2004-04" for April).


{{Anchor|Topic category|Topic categories|TOPICCAT}}{{anchor|Set category|Set categories|SETCAT}}
Using this method to sort category entries is sometimes informally referred to as ''the pipe trick''. However, this use of the pipe character is very different from the original Wikimedia ] which allows one to easily hide parenthetical disambiguation in links.
{{Shortcut|WP:TOPICCAT|WP:SETCAT}}
There are two main kinds of category:


* '''Topic categories''' are named after a topic (usually sharing a name with the Misplaced Pages article on that topic). For example, ] contains articles relating to the topic ].
It is possible to force an article or subcategory to the top of the list by using a non-alphanumeric character as the first after the pipe. For example, using <tt><nowiki>]</nowiki></tt> (note the space) or <tt><nowiki>]</nowiki></tt> would force that article to be displayed before all the others.
* '''Set categories''' are named after a class (usually in the plural). For example, ] contains articles whose subjects are cities in France. A category may be explicitly labeled as such using the {{tl|Set category}} template.


Sometimes, for convenience, the two types can be combined, to create a ''set-and-topic'' category (such as ], which contains articles about particular voivodeships as well as articles relating to voivodeships in general).
===Year categories===
In categories which are years, such as ], special sorting guidelines apply:
* Entries should generally be sorted by ''topic'', so the article ], for example, would contain the category reference <tt><nowiki>]</nowiki></tt> while ] would contain the reference <tt><nowiki>]</nowiki></tt>; ] would contain <tt><nowiki>]</nowiki></tt>.
* The article about the year itself, ], should be sorted first among all articles by using <tt><nowiki>]</nowiki></tt>.
* Articles for individual months, such as ], should be sorted ''chronologically'' in the first section on the category page, in this case using <tt><nowiki>]</nowiki></tt>.


{{anchor|SUBCAT|SUPERCAT}}
===Interlanguage links to categories===
=== Subcategorization ===
Interlanguage links work just as they do for regular articles; <tt><nowiki>]</nowiki></tt> in ] connects to the German counterpart. This can be a useful way to compare coverage, or to look for articles in need of interlanguage links. Note that the different languages may have adopted different standards and practices for categorization, so a given category might not exist in other languages.
{{Shortcut|WP:SUBCAT|WP:SUPERCAT}}
]
]). An item may belong to several subcategories of a parent category (as pictured).]]


If logical membership of one category implies logical membership of a second (an ] relationship), then the first category should be made a subcategory (directly or indirectly) of the second. For example, ] is a subcategory of ], which in turn is a subcategory of ].
==Tools==


Many subcategories have two or more parent categories. For example, ] should be in both ] and ]. 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;<ref>This condition can be formulated in terms of ] as follows: the directed graph that has the categories as vertices and the parent-child relationships as edges should be '']''.</ref> that is, no category should be contained as a subcategory of one of its own subcategories.{{#tag:ref|There is an exception to this for maintenance purposes. For example, ] is a direct subcategory of itself and of ] and ], each of which is a direct subcategory of ].}} 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.
* ] can be used to automatically move articles from one category to another, get dumps of the category trees, and accomplish some other useful category-related tasks.


Except for ] (see below), pages for subcategories should be categorised under the {{em|most specific}} parent categories possible.
==Current projects==


Sometimes proper subcategorization requires the ].
See: ]


Note also that as stub templates are for maintenance purposes, not user browsing (see ] above), they do ''not'' count as categorization for the purposes of Misplaced Pages'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.
==Known category-related bugs==


{{anchor|DIFFUSE}}
Please report new category-related bugs on and list them below.
====Diffusing large categories====
{{Shortcut|WP:DIFFUSE}}
{{redirect|WP:DIFFUSE|conflicts|Misplaced Pages:Diffusing conflict}}
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, ] contains no articles about specific rivers directly, they are all in subcategories.


{{anchor|Metacategories|META}}A category may be diffused using several coexisting schemes; for example, ] 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 ], but into the metacategory ], which itself appears in Category:Albums. (See ])
(Bugs higher than 1775 have not been checked)
===Redirects===
* ]
* ] (to show redirects next to the articles they redirect to in categories, when appropriate)
* ]
* ]
* ]
* ]


It is possible for a category to be only partially diffused—some members are placed in subcategories, while others remain in the main category.
===Special:Categories===
* ]
* ]
* ]
* ]


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 {{tl|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.)
===Large categories===
* ]
* ]
* ]
* ]


To suggest that a category is so large that it ought to be diffused, or substantially diffused, into subcategories, you can add the {{tl|overpopulated category}} template to the category page.
===Updating problems===
* ]
* ]


{{anchor|ALLINCLUDED|DUPCAT}}
===General===

* ]
====Non-diffusing subcategories====
* ]
{{Shortcut|WP:ALLINCLUDED|WP:DUPCAT}}
* ]

* ]
Not all subcategories serve the "diffusion" function described above; some are simply subsets which have some special characteristic of interest, such as ] as a subcategory of ]. 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 {{Tl|Non-diffusing subcategory}} templates should be used for subcategories that are non-diffusing, like {{cl|American novelists of Asian descent}}.
* ]
* The {{Tl|All included}} can be used for categories where all child articles of a certain type are in the parent, like {{cl|Presidents of the United States}} or {{cl|Mountains of Switzerland}}.
* ]

* ]
Subcategories defined by gender, ethnicity, religion, and sexuality should almost always be non-diffusing subcategories. The ] guideline outlines the rules on these categories in more detail.
* ] (the text you get for completely and partly empty category pages, category talk pages, etc.)

* ]
Note that some categories can be non-diffusing on some parents, and diffusing on others. For example, {{cl|British women novelists}} is a non-diffusing subcategory of {{cl|British novelists}}, but it is a diffusing subcategory of {{cl|Women novelists by nationality}}.
* ]

* ]
{{Anchor|Sort order|SORTKEY}}
* ]
==Sort keys==
* ]
{{shortcut|WP:SORTKEY}}
* ]
{{redirect|WP:Sorting|sorting of tables|Help:Sortable tables}}
* ]

* ]
'''Sort keys''' are sometimes needed to produce a correct ordering of member pages and subcategories on the category page. For the mechanics, see {{section link|Help:Category#Sorting category pages}}.
* ]

* ]
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 ].
* ]

* ]
Other sort key considerations (in no particular order):
* ]
* In English Misplaced Pages, sort order merges (ignores) case and diacritics. For example, "Baé", "Båf", "BaG" would be sorted in that order.<ref>In 2016, English Misplaced Pages's category collation was changed to "uca-default", which is based on the ] (UCA). The most noticeable difference is that UCA groups characters with diacritics with their non-diacritic versions. See {{Section link|Misplaced Pages talk:Categorization/Archive 16#OK to switch English Misplaced Pages's category collation to uca-default?}} and {{Section link|Misplaced Pages:Village pump (technical)/Archive 149#Sorting in categories unreliable for a few days}}.</ref>
* ]
* The main article/s of a category, if existent, should get sorted with a space as key so that it/they appear(s) at the very top of the category. Example: <code><nowiki>]</nowiki></code> Those articles are typically homonymous or at least synonymous to their category.<!--generally shouldn't exceed 3 articles; most of the time it should be a single one--> 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: <code><nowiki>]</nowiki></code> Those articles are typically called "History of example", "Types of example", "List of example" or similar.<!--generally shouldn't exceed 5 articles; most of the time it should be a single one-->
* ]
* ]&mdash;a, an, and the&mdash;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 <nowiki>{{DEFAULTSORT:Lady, The}}</nowiki>. 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 ] should be left as the default value (i.e. no <nowiki>{{DEFAULTSORT}}</nowiki> required).
* ]
* 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 ] should be <nowiki>{{DEFAULTSORT:Mister Bean}}</nowiki> and ] should be sorted <nowiki>{{DEFAULTSORT:Dungeons And Dragons}}</nowiki>. An exception is the times sign (×) as in "Men's 4 × 100 metre" relay; use the letter x in this case.
* ]
* Landforms (and similar) that have noun prefixes such as ] should have the noun sorted after as <nowiki>{{DEFAULTSORT:Mull, Isle of}}</nowiki>. However, this isn't usually done for settlements and administrative divisions; for example, while ] uses <nowiki>{{DEFAULTSORT:Wight, Isle of}}</nowiki>, the categories for the county/district are sorted "Isle of Wight". Also for settlements such as ] the prefix isn't moved.
* ]
* 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, ] is sorted <nowiki>{{DEFAULTSORT:Oneill, Eugene}}</nowiki>. 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 ] might have a sort key "John 9". To get the correct sort order zero padding may be required, thus the ''actual'' sort key in this case is "John 09" this ensures that ] sorts before ] – 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 ] 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 ] 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 ] the page ] would have the sort key "Film", and in ] the page ] 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 order of characters ''before'' numbers and Latin alphabet (0&ndash;9, A&ndash;Z) is (partial list):
:'''<code>! " # $ % & ' ( ) * + , - . / 0 9 : ; < = > ? @ ^ _ ` A Z a z { | } ~ É é &mdash;</code>'''
:''See also:'' ] for more information.
* Sort keys may be prefixed with ] to place entries ''after'' the main alphabetical list. The following letters have special meaning by convention:
** "]" (capital sigma) is used to place ] categories at the end of subcategory lists. ("µ" (]) was previously used, but the capital version "Μ" was confusing.)
** "]" (beta, displays as capital, "Β") is for ].
** "]" (delta) is for ], where sorting by Latin D is undesirable.
** "]" (iota, displays as "Ι") is for ].
** "]" (rho, displays as "Ρ") is for ].
** {{anchor|Tau}}"]" (tau, displays as "Τ") is for ]. Keep in mind, template categories should not be added to content categories per ].
** "]" (upsilon, displays as "Υ") for ].
** "]" (omega, displays as "Ω") is for ]s.
*: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 ].
*:'''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 <code><nowiki>{{DEFAULTSORT}}</nowiki></code> ] should be used. Per ], 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.

==Inappropriate categorization==
Anyone may edit an article and remove a questionable categorization. If an article has an "incorrect" or "inappropriate" category, remove that category from the article, and replace it (if applicable) with a more correct category.

Even if an article may occupy the grey areas of a category's inclusion criteria, that is not a valid reason to keep the article in a category. If a particular article does not fit the inclusion criteria of a category, ''then the article simply should not be added to it''.

If categorization of any particular page is ], please ] the categorization on the ] of the page in question. If the category seems reasonable, but questionable in some cases, consider whether you can solve (part of) the problem by writing a clearer ].

If you have a proposal for a better name for the category or for a wider re-arrangement of the categorization scheme; or if you have a concern that may apply to several members of the category (such as if the category violates one or more sections on this page, ], ], or other Misplaced Pages ]), you can participate in, or post a new, discussion about the category.

Category talk pages are not always widely ]. Consider whether you can ] to take part in a discussion, such as by discussing it at a relevant ], or at ]. Another option could be to nominate the category for discussion at ], or if the ] has an obvious typographical error, you can list it for speedy renaming at ].

''See ] for instructions on how to use the templates for: '''deletion''' ({{tl|cfd}}), '''renaming''' ({{tl|cfr}}), or '''merging''' ({{tl|cfm}}).''

If you are in a content dispute, see ] for what to do next.

==Category cleanup templates==
* Article with insufficient categories
** {{Tl|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 {{Tl|Recategorize}} template when there are too many categories. Put this template ''on the top'' of articles.
* Category unknown
** If you're not sure where to categorize a particular page, add the {{Tl|uncategorized}} template to it, and other editors (such as those monitoring ]) will help find appropriate categories for it.


==See also== ==See also==
* ] (information page summarizing key points of this guideline)
*] - A navigation page that includes links to high-level categories
*] * ]
*] * ]
* ]
*]
* ]
*] (original guidelines for category proposals and implementations)
*] - Material related to concept categorization. * ]
*] * ]
* ], script for moving subcategories between categories
*] is a proposal to restrict category creation to admins.
* ]
===Browsing categories===

*] - Category for categories that need reparenting.
===For browsing===
*] - Lists all existing categories alphabetically.
* ] (formerly CatScan)
*] - List of top-level categories. Requires this category be defined on the top of a tree.
* ] (category tree jumping)
*] - Fundamental knowledge categories.
* ] (ability to find articles that are in more than one category)
* ] (lists all existing categories alphabetically)
* ]
* ]

===For maintenance===
* ]
* ]
* ]
* ]
* ]
* ]
* ]
* ]
* ]

==Notes==
{{reflist}}


{{Misplaced Pages policies and guidelines}}
<!--Categories -->
] {{Misplaced Pages categorization navbox}}


]
]
]
]
] ]
] ]
]
]
]
]
]
]
]
]
]
]
]
]
]
]

Latest revision as of 04:51, 15 December 2024

Guidance on the proper use of the categorization function in Misplaced Pages

"WP:CATEGORY" and "WP:CAT" redirect here. You may be looking for Misplaced Pages:Contents/Categories (a list of top-level categories), WikiProject Cats, Misplaced Pages:HotCat, WikiProject Categories, or even Misplaced Pages:WikiCat. For the category system itself, see Category:Contents. "WP:CG" redirects here. For the internal project on computer-generated imagery, see Misplaced Pages:WikiProject Computer graphics.
Blue tickThis page documents an English Misplaced Pages editing guideline.
Editors should generally follow it, though exceptions may apply. Substantive edits to this page should reflect consensus. When in doubt, discuss first on this guideline's talk page.
Shortcuts
Misplaced Pages guidelines
Behavioral
Discussions
Content
Editing
Categorization
Style
Deletion
Project content
Other
Search


For information on the mechanics of the function, category syntax, etc., see Help:Category. For quick answers, see Misplaced Pages:FAQ/Categorization.

This page contains guidance on the proper use of the categorization function in Misplaced Pages. The central goal of the category system is to provide navigational links to pages in Misplaced Pages within a hierarchy of categories. Using essential, defining characteristics of a topic, readers can browse and quickly find sets of pages on topics that are defined by those characteristics.

For proposals to delete, merge, or rename categories, follow the instructions at Categories for discussion. Please use it before undertaking any complicated re-categorization of existing categories or mass creation of new categories.

Categorizing pages

A screencast showing how to categorise pages and explaining the usage of HotCat
Further information: Help:Category See also: Misplaced Pages:Categorization dos and don'ts and Misplaced Pages:Categorizing redirects

Every Misplaced Pages page should belong to at least one category, except for talk pages, redirects, and user pages, which may optionally be placed in categories where appropriate.

Shortcuts

Each categorized page should be placed in all of the most specific categories to which it logically belongs. And pages should not normally be placed in both a given category and any of its sub- or parent (super-) categories. For exceptions to this, see § Eponymous categories and § Non-diffusing subcategories.

This means that if a page belongs to a subcategory of C (or a subcategory of a subcategory of C, and so on) then it is not normally placed directly into C.

  • For example, the article "Paris" need only be placed in Category:Cities in France, not also in Category:Populated places in France. 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.

Since all categories form part of a tree-like hierarchy, do not add categories to pages as if they are tags.

Creating category pages

Shortcut

Before creating a new category

Main pages: Misplaced Pages:Categories, lists, and navigation templates and Misplaced Pages:Overcategorization See also: Help:Sortable tables Shortcut

Categories are not the only means of enabling users to browse sets of related pages. And categories have several disadvantages, including that categories only show the page name of each page being categorized, therefore:

  • While the category description may provide broader information, individual category members cannot be annotated with descriptions or comments, so they give no context or elaboration for any specific entry.
  • There is no provision for referencing any specific entry, to verify a page meets a category's criteria of inclusion.

So, consider whether a list would be more appropriate for such a grouping of pages. Lists would also be more useful where it is important to see dates, for example, a list of Nobel laureates. And can provide options for sorting the entries.

Also, consider whether the category might be considered category clutter. Please see Misplaced Pages:Overcategorization, for more information on this.

Choosing a name for the category

Main page: Misplaced Pages:Category names See also: § Naming conventions

A good category name is accurate and neutral, and, as much as possible, defines the category's inclusion criteria in the name itself.

Important: Moving non-conventionally categorized pages to another category name (see {{Category redirect}}) imposes an additional overhead – an edit for every categorized page and subcategory.

So, when choosing a name for the category, please be sure a similar category does not exist. Before creating a category, try to find it under a similar name. You can search existing category names as described here (top of page). Another way to determine if suitable categories already exist for a particular page is to check the categories of pages concerning similar or related topics.

Note: Eponymous categories (categories whose name and topic is the same as an article, such as a category named after a person) should only be created if enough directly related articles exist.

Creating the category

After you have determined an appropriate category name for the category, next try to find a suitable place for the new category. (For example, categories of people should be in the tree of "people" categories.) Please see #Category tree organization for more information on this.

Once you have determined where to categorize this new category, you should be ready to create the new category.

To create a category:

  1. Add a page to the intended category. Do this by editing that page, and add the name of the new category: (e.g.: ] )
    • ShortcutBy convention, categories 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.
  2. Save your edit. The as-yet-undefined category name will now appear as a red link in the category list at the bottom of the page.
    • Shortcut A page 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.
  3. Next, click on that red link, which brings you to the new category page to create.
  4. Finally, at the bottom of the category page, simply add the parent category (e.g.: ] ), which should usually be a hypernym of the subcategory. This will add the new category into the appropriate parent category.

Nota bene* If something goes wrong, double check to see if you followed the steps properly and check if the wikitext is correct. For example, if the category fails to list in the parent category, the wikitext should be ], not ].

Category description

Shortcut

While it should typically be clear from the name of an existing category which pages it should contain, sometimes, a common-sense guess based on the name of the category isn't enough to figure out whether a page should be listed in the category. So, rather than leave the text of a category page empty (containing only parent category declarations), adding a main article which describes the topic, can help with that.

However, only linking to a Misplaced Pages article explaining the title is often not sufficient as a description for a category. It can be helpful – to both readers and editors – to include a clear description of the category, indicating what pages it should contain, how they should be subcategorized, and so on, and linking to one or more pages as background information.

In such cases, the desired contents of the category should be described on the category page, similar to how the list selection criteria are described in a stand-alone list. The category description should make direct statements about the criteria by which pages should be selected for inclusion in (or exclusion from) the category. This description, not the category's name, defines the proper content of the category. Do not leave future editors to guess about what or who should be included from the title of the category. Even if the selection criteria might seem obvious to you, an explicit standard is helpful to others, especially if they are less familiar with the subject.

The description can also contain links to other Misplaced Pages pages, in particular to other related categories which do not appear directly as subcategories or parent categories, and to relevant categories at sister projects, such as Commons. Another technique that can be used is described at Misplaced Pages:Classification. Like disambiguation pages, category pages should not contain either citations to reliable sources or external links.

Various templates have been developed to make it easier to produce category descriptions; see Category namespace templates. There are hatnote templates including {{Category main article}} and {{Category see also}}; others are listed at Misplaced Pages:Hatnote#Categories.

Additional considerations

Categories may have hundreds of members, displayed over many pages, with, at most, only 200 category entries on a single category page. To make navigating large categories easier, a table of contents can be used on the category page. The following templates are some of the ways of doing this:

  • {{Category TOC}} – adds a complete table of contents (Top, 0–9, A–Z)
  • {{Large category TOC}} – adds a complete table of contents with five subdivisions for each letter (Aa Ae Aj Ao At)
  • Consider using {{CatAutoTOC}} which uses the appropriate TOC for the number of pages on a category page.

Likewise, a maximum of 200 subcategories are displayed at a time, so some subcategories may not be immediately visible. To display all subcategories at once, add a category tree to the text of the category page, as described at Help:Category § Displaying category trees and page counts.

Category pages can have interlanguage links in the "Languages" list in the left sidebar (in the default skin), linking to corresponding categories in other language Wikipedias. To edit these on Wikidata, click on the "Edit links" link at the end of the languages list.

Categorization of articles

Naming conventions

Main page: Misplaced Pages:Category names This section is transcluded from Misplaced Pages:Categorization/Naming. (edit | history)

Topic and set categories

  • Names of topic categories should be singular, normally corresponding to the name of a Misplaced Pages article. Examples: "Law", "France", "Hillary Clinton".
  • Names of set categories should be plural. Examples: "Writers", "Villages in Poland".
  • Note that in many instances a topic category and a set category have similar names, the topic category being singular and the set category plural. For example, Opera is a topic category (containing all articles relating to the topic), while Operas is a set category (containing articles about specific operas). Be careful to choose the right one when categorizing articles.

Categorizing articles

For category types to avoid, see Misplaced Pages:Overcategorization.

In general, categories of articles must be:

  • Shortcuts Verifiable: It should be clear from verifiable information in the article why it was placed in each of its categories. Use the {{Unreferenced 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.
  • Shortcuts Neutral: 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.
  • Shortcuts Defining: Defining characteristics of an article's topic are central to categorizing the article. A defining characteristic is one that reliable sources commonly and consistently refer to in describing the topic, such as the nationality of a person or the geographic location of a place.
    For example, Italian and artist are defining characteristics of Caravaggio, because virtually all reliable sources on the topic mention them, so that article is included in categories such as Category:Italian Baroque painters.
Be sure to include categories for all defining characteristics. For non-defining characteristics, editors should use their judgment to choose which additional categories (if any) to include.
For example, Caravaggio is included in the non-defining category of Category:Deaths from sepsis.

Categorizing articles about people

Main page: Misplaced Pages:Categorizing articles about people See also: Category:People Shortcut
  • For articles about people, categorize by characteristics of the person the article is about, not characteristics of the article: e.g., do not add ] to an article. Sub-categories of Category:Biography (genre) may legitimately contain articles about biographical films or biographical books, but should not contain articles about individual people. The article is a biography; the topic of the article – the person – is not.
  • Keep articles about people separate. Categories with a title indicating that the contents are people, should normally only contain biographical articles and lists of people, and perhaps a non-biographical main article, though this can also be added at the top of the category. This is for clarity and ease of use, and to preserve the integrity of category tree of people articles.

Categorizing articles about works

See also: Category:Creative works and Misplaced Pages:Category names § Works of art categories by subject

Categorizing list pages

See also: Category:Lists

If there are more than a few lists in a particular subject area, it may be appropriate to create a specific subcategory that contains only the list pages and no other types.

When placing list pages in such a category, use a sort key to adjust the page title to exclude the starting words "List of", or all lists would appear under "L".

  • For example, when adding List of Soviet Republics to the category, using ] and will make it be sorted in the S section.

Eponymous categories

Shortcuts See also: Category:Eponymous categories and Category:Misplaced Pages categories named after people For the overuse of the word "eponymous" on Misplaced Pages, see WP:TITULAR.

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; Abraham Lincoln and Category:Abraham Lincoln).

Eponymous categories should not be created unless enough directly related articles or subcategories exist. However, this should not be done simply to reduce the number of categories displayed in an article.

An eponymous category should have only the categories of its article that are relevant to the category's content. For example:

Articles with eponymous categories
"WP:CATMAIN" redirects here. For the template, see Template:Category main article. Shortcut
  • The article itself should be a member of the eponymous category. It should be sorted with a space, so that it appears at the start of the category listing (see § Sort keys below).
  • The article should be listed as the main article of the category using the {{Category main article}} 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:Countries in 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:
  1. Keep both the eponymous category and the main article in the parent category. This is used in Category:Countries in Europe to allow that region's country articles to be navigated together.
  2. Keep just the child article. This is used in Category:British Islands, to prevent a loop.
  3. Keep just the eponymous category. This is used for Category:Farmers 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:Misplaced Pages categories named after American politicians.

Categorizing draft pages

Shortcut Further information: Misplaced Pages:Drafts § Preparing drafts

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 those categories. This can be done either by inserting a colon character to link to each category (e.g. change ] to ]), or by wrapping them in {{Draft categories}} (e.g.{{draft categories|1=] ]}} etc.). After you move the draft into article space, remove the leading colons to re-enable the categories. If using the draft categories template, the categories will automatically work as normal in mainspace, but the template should be removed. The same system may be used in a new draft to list the categories it may have when moved to mainspace.

Two scripts are available to help with these tasks: User:DannyS712/Draft no cat and User:DannyS712/Draft re cat.

Drafts may be placed in the appropriate subcategories of Category:Misplaced Pages drafts.

Categorizing project pages

Misplaced Pages administrative categories

Shortcut Further information: Misplaced Pages:Administration § Data structure and development

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.

Files

Shortcut Further information: Misplaced Pages:Manual of Style/Images § Image description pages

Category tags should be added to file pages of files that have been uploaded to Misplaced Pages. 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:Misplaced Pages files. To categorize a new file when uploading, simply add the category tag to the upload summary.

Freely licensed files should be uploaded to, and categorized on, Wikimedia Commons, instead of uploading and categorizing on Misplaced Pages. Existing freely licensed files should usually be moved from Misplaced Pages to Commons, with a mirror page automatically remaining on Misplaced Pages. (For an example of one such mirror page, see here.) Categories should not be added to these Misplaced Pages mirror pages, because doing so creates a new Misplaced Pages 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 Misplaced Pages Main Page in the Did You Know? column.

Images that are used in Misplaced Pages 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.

Templates

Shortcut See also: Template:Documentation

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:Misplaced Pages 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 navigational boxes, 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. When a <noinclude>...</noinclude> block is the last item in the template code, there should be no spaces or new lines between the last part of the template proper and the opening <noinclude> tag.

User pages

Shortcut Further information: Misplaced Pages:User categories and Misplaced Pages:User pages § Categories, templates that add categories, and redirects

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, wrap them inside {{Draft 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.

Also, do not transclude articles into your user pages: this will result in the user page being included in all the article's categories.

At Database reports/Polluted categories, a list of affected categories is maintained.

Categorization using templates

Shortcuts

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. See Template:Infobox roller coaster for an example that only adds a category by manufacturer if it exists, and otherwise uses a hidden category.

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

Shortcut See also: mw:Help:Categories § Hidden 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 {{Misplaced Pages 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 Misplaced Pages:Categories for discussion § Redirecting categories for the policy, and Misplaced Pages:Redirect § Category redirects for the technical details.

Category tree organization

Shortcut
Partial view of Misplaced Pages's category system from 2007. Arrows point from category to subcategory.

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.)

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.

Shortcuts

There are two main kinds of category:

  • Topic categories are named after a topic (usually sharing a name with the Misplaced Pages 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

Shortcuts
A tree structure showing the possible hierarchical organization of an encyclopedia
Items may belong to more than one category, but normally not to a category and its parent (there are, however, exceptions to this rule, such as non-diffusing categories). An item may belong to several subcategories of a parent category (as pictured).

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; that is, no category should be contained as a subcategory of one of its own subcategories. 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 subcategories 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 § Misplaced Pages administrative categories above), they do not count as categorization for the purposes of Misplaced Pages'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

Shortcut "WP:DIFFUSE" redirects here. For conflicts, see Misplaced Pages:Diffusing conflict.

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 contains no articles about specific rivers directly, they are all in subcategories.

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, or substantially diffused, into subcategories, you can add the {{overpopulated category}} template to the category page.

Non-diffusing subcategories

Shortcuts

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. 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:

Subcategories defined by gender, ethnicity, religion, and sexuality should almost always be non-diffusing subcategories. The Misplaced Pages:Categorizing articles about people 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 subcategory of Category:British novelists, but it is a diffusing subcategory of Category:Women novelists by nationality.

Sort keys

Shortcut "WP:Sorting" redirects here. For sorting of tables, see Help:Sortable tables.

Sort keys are sometimes needed to produce a correct ordering of member pages and subcategories on the category page. For the mechanics, see Help:Category § Sorting category pages.

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 Misplaced Pages, sort order merges (ignores) case and diacritics. For example, "Baé", "Båf", "BaG" would be sorted in that order.
  • The main article/s of a category, if existent, should get sorted with a space as key so that it/they appear(s) at the very top of the 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: ] 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).
  • 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.
  • 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.
  • 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 in this case 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 order of characters before numbers and Latin alphabet (0–9, A–Z) is (partial list):
! " # $ % & ' ( ) * + , - . / 0 9 : ; < = > ? @ ^ _ ` A Z a z { | } ~ É é —
See also: Meta:Help:Sorting#Sort modes for more information.
  • 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 Misplaced Pages 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 MOS:ORDER, 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.

Inappropriate categorization

Anyone may edit an article and remove a questionable categorization. If an article has an "incorrect" or "inappropriate" category, remove that category from the article, and replace it (if applicable) with a more correct category.

Even if an article may occupy the grey areas of a category's inclusion criteria, that is not a valid reason to keep the article in a category. If a particular article does not fit the inclusion criteria of a category, then the article simply should not be added to it.

If categorization of any particular page is disputed, please discuss the categorization on the talk page of the page in question. If the category seems reasonable, but questionable in some cases, consider whether you can solve (part of) the problem by writing a clearer #Category description.

If you have a proposal for a better name for the category or for a wider re-arrangement of the categorization scheme; or if you have a concern that may apply to several members of the category (such as if the category violates one or more sections on this page, Misplaced Pages:Categorizing articles about people, Misplaced Pages:Overcategorization, or other Misplaced Pages policies and guidelines), you can participate in, or post a new, discussion about the category.

Category talk pages are not always widely watched. Consider whether you can invite more potentially interested people to take part in a discussion, such as by discussing it at a relevant WikiProject, or at Misplaced Pages:WikiProject Categories. Another option could be to nominate the category for discussion at Misplaced Pages:Categories for discussion, or if the category name has an obvious typographical error, you can list it for speedy renaming at Misplaced Pages:Categories for discussion/Speedy.

See Misplaced Pages:Categories for discussion/Howto for instructions on how to use the templates for: deletion ({{cfd}}), renaming ({{cfr}}), or merging ({{cfm}}).

If you are in a content dispute, see Misplaced Pages:Dispute resolution for what to do next.

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.
  • Category unknown

See also

For browsing

For maintenance

Notes

  1. in declarative statements, rather than table or list form
  2. Mathematically speaking, this means that the system approximates a directed acyclic graph.
  3. 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.
  4. There is an exception to this for maintenance purposes. For example, Category:Hidden categories is a direct subcategory of itself and of Category:Misplaced Pages extended-confirmed-protected pages and Category:Container categories, each of which is a direct subcategory of Category:Hidden categories.
  5. In 2016, English Misplaced Pages'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 Misplaced Pages talk:Categorization/Archive 16 § OK to switch English Misplaced Pages's category collation to uca-default? and Misplaced Pages:Village pump (technical)/Archive 149 § Sorting in categories unreliable for a few days.
Misplaced Pages key policies and guidelines (?)
Content (?)
P
G
Conduct (?)
P
G
Deletion (?)
P
Enforcement (?)
P
Editing (?)
P
G
Style
Classification
Project content (?)
G
WMF (?)
P
Misplaced Pages categorization
Guidelines
Help pages
Discussions
Projectspace essays
Userspace essays
Categories: