ଉଇକିପିଡ଼ିଆ:Categorization ନିମନ୍ତେ ଆଧାର ଦେଖିବେ

{{dablink|Multiple shortcuts redirect here, you may be looking for: [[Wikipedia:WikiProject Cats|WikiProject Cats]], [[Wikipedia:WikiProject Categories|WikiProject Categories]] or [[Help:Sorting]].}}
{{subcat guideline|editing guideline|Categorization|WP:CAT|WP:CATEGORY}}
{{Guideline list}}
[[File:Category explanation.ogv|thumb|A screencast explaining categories at Wikipedia and the usage of [[User:TheDJ/HotCat|HotCat]]]]
This page contains guidance on the proper use of the '''categorization''' function in Wikipedia. For information on the mechanics of the function, category syntax, etc., see '''[[Help:Category]]'''. For quick answers, see the '''[[Wikipedia:FAQ/Categorization|Categorization FAQ]]'''. For the naming of categories, see [[Wikipedia:Category names]]. For the category system itself, see [[:Category:Contents]].

==The category system==
Wikipedia's category system can be thought of as consisting of overlapping [[tree (graph theory)|trees]]. Any category may branch into '''subcategories''', and it is possible for a category to be a subcategory of more than one parent. (A is said to be a '''parent category''' of B when B is a subcategory of A). Mathematically speaking, this means that the system approximates a [[directed acyclic graph]]. 

There is one top-level category, [[:Category:Contents]]. All other categories are found below this. Hence every category apart from this top one must be a subcategory of at least one other category.

There are two main kinds of category:
*'''Topic categories''' are named after a topic (usually sharing a name with the Wikipedia article on that topic). For example, [[:Category:France]] contains articles relating to the topic [[France]].
*'''Set categories''' are named after a class (usually in the plural). For example, [[:Category:Cities in France]] contains articles whose subjects are cities in France.

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).

If logical membership of one category implies logical membership of a second, then the first category should be made a subcategory (directly or indirectly) of the second. For example, [[:Category:Cities in France|Cities in France]] is a subcategory of [[:Category:Populated places in France|Populated places in France]], which in turn is a subcategory of [[:Category:Geography of France|Geography of France]].
[[Image:Category-diagram.png|thumb|300px|thumb|left|Partial view of Wikipedia's category system. Note how the arrows point downwards.]]
{{clearleft}}

==Categorizing pages==
Which pages a given category is supposed to contain is generally clear from the name of the category. Additional explanation may be placed in the text of the category page.

Pages are not placed directly into every possible category, only into the most specific one in any branch. 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 exceptions to this rule, see [[#Eponymous categories|Eponymous categories]] and [[#Non-diffusing subcategories|Non-diffusing subcategories]] below.

Every Wikipedia ''article'' should belong to at least one category. Normally a new article will fit into existing categories – compare articles on similar topics to find what those categories are. If you think a new category needs to be created, see [[#What categories should be created|What categories should be created]] below. If you don't know where to put an article, add the {{tl|uncategorized}} template to it – other editors (such as those monitoring [[Wikipedia:WikiProject Categories/uncategorized]]) will find good categories for it.

For information on whether and how to categorize pages other than articles, see [[#Non-article and maintenance categories|Non-article and maintenance categories]] below.

Particular considerations for categorizing articles:
*Each article should be placed in all of the most specific categories to which it logically belongs.
*It should be clear from [[WP:V|verifiable]] information in the article why it was placed in each of its categories. Use the {{tl|Category unsourced}} template if you find an article in a category that is not shown by sources to be appropriate, or the {{tl|Category relevant?}} template if the article gives no clear indication for inclusion in a category.
*Categorize articles by characteristics of the ''topic'', not characteristics of the ''article''. A biographical article about a specific person, for example, does not belong in [[:Category:Biography]].
*Articles on fictional subjects should not be categorized in a manner that confuses them with real subjects.
*An article should never be left with a non-existent ([[WP:REDLINK|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.
*By convention, category declarations are placed at the end of the wikitext, but before any [[WP:Stub|stub]] templates (which themselves transclude categories) and [[Help:Interwiki linking|interlanguage links]].
*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. If an article has an eponymous category (see [[#Eponymous categories|below]]), then that category should be listed first of all. For example, [[:Category:George Orwell]] is listed before other categories on the [[George Orwell]] page.
*If the desired display text in a particular category is different from the title of the article, it may be appropriate to categorize a redirect, either instead of or along with the article itself. For example, if John Smith was notable as both a musician and a writer, but used the stage name Johnny Rocket in his musical career, then the musician category declarations can be placed on the "Johnny Rocket" redirect page as well as (or instead of) on "John Smith". (Redirects appear in ''italics'' in category listings.) See also [[Wikipedia:Categorizing redirects]].

==What categories should be created==
Categories should be useful for readers to find and navigate sets of related articles. They should be the categories under which readers would most likely look if they were not sure of where to find an article on a given subject. They should be based on essential, "defining" features of article subjects, such as nationality or notable profession (in the case of people), type of location or region (in the case of places), etc. Do not create categories based on incidental or subjective features. Examples of types of categories which should not be created can be found at [[Wikipedia:Overcategorization]].
 
Remember that categories are not the only means of enabling users to browse sets of related articles. Other tools which may be used instead of or alongside categories in particular instances include lists and navigation boxes. For a comparison of these techniques, see [[Wikipedia:Categories, lists, and navigation templates|Categories, lists and navigation templates]].

Categorizations appear on pages without annotations or referencing to justify or explain their addition; editors should be conscious of the need to maintain a [[WP:NPOV|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.

Before creating a new category, check whether a similar category already exists under a different name (for example, by looking on the likely member pages or in likely parent categories).

Categories follow the same [[Wikipedia:Article titles|general naming rules]] as articles; for example, common nouns are not automatically capitalized. For specific rules, see [[Wikipedia:Naming conventions (categories)]].

For proposals to delete, merge, or rename categories, follow the instructions at [[Wikipedia:Categories for discussion|Categories for discussion]].

==Subcategorization==
{{shortcut|WP:SUBCAT}}

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]]. When making one category a subcategory of another, ensure that the members of the first really can be expected (with possibly a few exceptions) to belong to the second also.  Category chains formed by parent-child relationships should never form closed loops. 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.

===Diffusing large categories===
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Although there is no limit on the size of categories, a large category will often be broken down ("diffused") into smaller, more specific subcategories. For example, [[:Category:Rivers of Europe]] is broken down by country into the subcategories [[:Category:Rivers of Albania|Rivers of Albania]], [[:Category:Rivers of Andorra|Rivers of Andorra]], etc.

A category may be diffused using several coexisting schemes; for example, [[:Category:Albums]] is broken down by artist, by date, by genre etc. '''Metacategories''' may be created as ways of organizing schemes of subcategories. For example, the subcategories called "''Artistname'' albums" are not placed directly into [[:Category:Albums]], but into the metacategory [[:Category:Albums by artist]], which itself appears in [[:Category:Albums]].

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 {{tl|catdiffuse}} template, which indicates that any pages which editors might add to the main category should be moved to the appropriate subcategories when sufficient information is available. (If the proper subcategory for an article does not exist yet, either create the subcategory or leave the article in the parent category for the time being.)

To suggest that a category is so large that it ought to be diffused into subcategories, you can add the {{tl|verylarge}} template to the category page.

===Non-diffusing subcategories===
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Not all subcategories serve the "diffusion" function described above; some are simply subsets which have some special characteristic of interest, such as [[:Category:Best Actor Academy Award winners|Best Actor Academy Award winners]] as a subcategory of [[:Category:Film actors|Film actors]], [[:Category:Toll bridges in New York City|Toll bridges in New York City]] as a subcategory of [[:Category:Bridges in New York City|Bridges in New York City]], and [[:Category:Musical films|Musical films]] as a subcategory of [[:Category:Musicals|Musicals]]. These are called '''non-diffusing subcategories'''. They sometimes 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.)

It is useful to identify non-diffusing subcategories with a note on the category page. The {{tl|allincluded}} and {{tl|distinguished subcategory}} templates can be used.

Subcategories defined by ethnicity and sexuality are often non-diffusing subcategories. See also the [[Wikipedia:Categorization/Gender, race and sexuality|gender, race and sexuality]] categorization guideline.

===Eponymous categories===
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{{See also|Category:Eponymous categories}}
Often an article and a topic category will share the same name, as in  [[George W. Bush]] and [[:Category:George W. Bush]], or occasionally similar names referring to the same thing, as with [[Mekong]] and [[:Category:Mekong River]]. Such a category is called an '''eponymous category'''. Usually the article itself will be a member of the category (and should be sorted to appear at the start of the listing, as described below under [[#Sort keys|Sort keys]]). A clear link to the main topic article from an eponymous category page can be created using the template {{tl|cat main}}.

The question arises as to whether eponymous categories should be placed in (made subcategories of) the categories which their corresponding articles belong to. Logically they usually should not (for example, [[France]] belongs to [[:Category:European countries]], but [[:Category:France]] does not constitute a subset of European countries). However, by convention, many categories ''do'' contain their articles' eponymous categories as subcategories, even though they are not "true" subcategories. In any case, '''an article should not be excluded from any set category on the grounds that its eponymous category is made a "subcategory" of that category.'''

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 [[:Category:American politicians]] and [[:Category:Categories named after American politicians]].

==Sort keys==
{{Redirect|WP:SORT|sortable tables|Help:Sorting}}
{{shortcut|WP:SORT|WP:SORTKEY}}
'''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#Sort order|Sort order]]''' on the help page.

Because the software uses [[Unicode]] rather than true alphabetical ordering (see [[Help:Category#Sort order|details]]), it is important that sort keys be capitalized consistently. By convention, the first letter of each word in a sort key is capitalized, and other letters are lower case. For example, use "Dubois" in sort keys rather than "DuBois".

Categories of people are usually sorted by last name rather than first name, so "surname, forename" sort keys are used (as in "Washington, George"). For more information, see [[Wikipedia:Categorization of people#Ordering names in a category|Ordering names in a category]] in the people categorization guideline.

Entries containing modified letters should be sorted as if the letters were unmodified (for example, [[Łódź]] has the sort key "Lodz").

Other sort key considerations:
*Leading articles—a, an, and the—are one of the most common reasons for using sortkeys. Please also apply these sort keys to deliberate misspellings of these words—e.g. "da" or "tha" for "the."
*Entries containing numbers sometimes need special sort keys to ensure numerical rather than alphabetical ordering (for example, 19 and 103 come before 2 in alphabetical order, and IX comes before V). So [[Haydn]]'s 13th symphony might have the sort key "Symphony 013", the zero ensuring that it is listed before symphonies 100–108; Pope John IX might have a sort key "John 09". 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 a space as the sort key for an article matching an [[#Eponymous categories|eponymous category]], or for a [[Wikipedia:Glossary#Key article|key article]] for the category. For example, the article [[Barack Obama]] includes the category sort key <code><nowiki>[[Category:Barack Obama| ]]</nowiki></code>. This places the article at the start of the listing for that category. (Note: if the key article should not be a member, simply list it in the category text itself.) Typically, these eponymous categories are listed ''first'' even if they do not appear first in alphabetical order.
*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. The same technique is sometimes used to bring particular subcategories to the start of the list.
*To place entries ''after'' the main alphabetical list, use sort keys beginning with tilde ("~"). Other characters used for this purpose are "µ", commonly used to place [[WP:STUB|stub]] categories at the end of subcategory lists; "β" for [[Wikipedia:Books|book]] subcategories; and "τ" for templates.
*If a page is to be given the same sort key in all or several of its categories, the <code><nowiki>{{DEFAULTSORT}}</nowiki></code> [[Help:Magic words|magic word]] can be used. Conventionally, 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.

==Content of category pages==
Rather than leave the text of a category page empty (containing only parent category declarations), it is helpful – to both readers and editors – to include a description of the category, indicating what pages it contains, how they should be subcategorized, and so on. The description can also contain links to other pages, in particular to other related categories which do not appear directly as subcategories or parent categories, and to "sister categories" on other projects, such as [[Wikipedia:Commons|Commons]].

Various templates have been developed to make it easier to produce category descriptions, such as {{tl|Cat main}}, {{tl|Cat see also}}, and {{t|Related category}}. For more of these, see [[:Category:Category namespace templates|Category namespace templates]]. Another technique that can be used is described at [[Wikipedia:Classification]].

A maximum of 200 category entries are displayed per screen. 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|CategoryTOC}} – adds a complete table of contents (Top, 0–9, A–Z)
*{{Tl|CatAZ}} – the same as {{tl|CategoryTOC}}, but without the numbers 0–9
*{{Tl|LargeCategoryTOC2}} – adds a complete table of contents with five subdivisions for each letter (Aa Ae Aj Ao At) 
*{{Tl|LargeCategoryTOC}} –  adds a complete table of contents with twenty-six subdivisions for each letter (Aa ... Az) 

Subcategories are split alphabetically along with the articles, which means that the initial screen of a split category may not include all its subcategories. To make all subcategories display on each screen, add a category tree to the text of the category page, as described at the help page under [[Help:Category#Displaying category trees and page counts|Displaying category trees and page counts]].

[[Help:Interlanguage links|Interlanguage links]] work on category pages just as they do for articles, and can be used to link to corresponding categories on other language Wikipedias.

==Non-article and maintenance categories==
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A distinction is made between two types of category:
*'''content categories''', intended as part of the encyclopedia, to help readers find articles, based on features of the subjects of those articles;
*'''project 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.

Project categories include '''stub categories''' (generally produced by [[WP:STUB|stub]] templates), '''maintenance categories''' (often produced by tag templates such as {{tl|cleanup}} and {{tl|fact}}, and used for [[WP:Maintenance|maintenance]] projects), [[WP:WikiProject|WikiProject]] and assessment categories, and categories of pages in non-article [[WP:NAMESPACE|namespaces]].

Article pages should be kept out of project 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 a project 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 under [[#Hiding categories|Hiding categories]] below.

There are separate project categories for different kinds of non-article page ([[WP:template|template]] categories, [[Wikipedia:Disambiguation|disambiguation page]] categories, [[WP:Project namespace|project page]] categories, etc.). There is no need to categorize [[WP:User page|user pages]], [[WP:talk page|talk page]]s or [[WP:redirects|redirects]], although these can be placed in categories where appropriate. See the guideline on [[Wikipedia:Categorizing redirects|categorizing redirects]], and the [[#Categorizing user pages|Categorizing user pages]] section below.

===Images===
Category tags can be added to image pages too. Images 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 image category can be created. An image category is typically a subcategory of the general category about the same subject, and a subcategory of the wider image category, [[:Category:Wikipedia images|Wikipedia images]]. To categorize a new image when uploading, simply add the category tag to the [[Help:Edit summary#File_upload_summary|upload summary]].

=== {{anchor|User namespace}}Categorizing user pages===
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[[Help:User page|User page]]s are not articles, and thus do not belong in content categories such as [[:Category:Living people|Living people]] or [[:Category:Biologists|Biologists]]. They can however be placed in '''user categories''' – subcategories of [[:Category:Wikipedians|Wikipedians]], such as [[:Category:Wikipedian biologists|Wikipedian biologists]] – which assist collaboration between users. See [[Wikipedia:User categories]] for further information.

Similarly, user subpages that are draft versions of articles should be kept out of content categories. If you copy an article from mainspace to userspace and it already contains categories, remove them or comment them out. Restore the categories when you move the draft back into article space.

===Hiding categories===
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In cases where, for technical reasons, project 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 [[WP:stub|stub]] categories or "uncategorized article" categories – these types are ''not'' hidden.

To hide a category, add the template {{tl|hiddencat}} to the category page (the template uses the [[WP:Magic word|magic word]] <nowiki>__HIDDENCAT__</nowiki>). 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 [[Special:Preferences|My Preferences]]. Notice that "hidden" parent categories are never in fact hidden on category pages (although they are listed separately).

== Categorization using templates ==
Many [[WP:Template|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 ''project'' categories, including stub categories and maintenance categories.

However, it is recommended that articles should 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; ordering of categories on the page is less controllable; and the "incategory" [[WP:Searching|search term]] will not find such pages <ref>[[bugzilla:2285]]</ref>.

When templates are used to populate project categories, ensure that the code cannot generate nonsensical or non-existent categories, particularly when the category name depends on a parameter. Also, see [[Wikipedia:Category suppression|Category suppression]] for ways of keeping inappropriate pages out of template-generated categories.

Category declarations in templates often use <nowiki>{{PAGENAME}}</nowiki> as the sort key, particularly if they are designed to be placed on talk pages, as this suppresses the ''Talk:'' prefix. Note that this overrides any DEFAULTSORT defined on the page.

==Redirected categories==
Because of software limitations <ref>[[bugzilla:3311]]</ref>, ordinary (hard) [[WP:Redirect|redirects]] should ''not'' be used with category pages. If a category name needs to be redirected to another, use the {{tl|Category redirect}} template to create a '''soft redirect'''.  A [[Wikipedia:Bot|bot]] traverses categories redirected in this manner, moving articles out of the redirected category into the target category. (See [[Template talk:Category redirect]].)

==See also==
*[[Wikipedia:Overcategorization]]
*[[Wikipedia:Categorization of people]]
*[[Wikipedia:Categorizing redirects]]
*[[Wikipedia:Categories, lists, and navigation templates]]
*[[Wikipedia:Category suppression]]
*[[Wikipedia:WikiProject Categories]]
*[[m:Association of Categorist Wikipedians|Association of Categorist Wikipedians]]
*[[m:Help:Sorting|Sortable tables]]

;For browsing
*[[Wikipedia:Classification]] (category tree jumping)
*[[Special:CategoryTree]] 
*[[Wikipedia:CatScan]]
*[[:Category:Categories]]
*[[Special:Categories]] (lists all existing categories alphabetically)

;For maintenance
*[[Special:Uncategorizedpages]]
*[[Special:Uncategorizedimages]]
*[[Special:Uncategorizedcategories]] (not currently updated)
*[[Special:Unusedcategories]]
*[[Special:Wantedcategories]]
*[[Special:Mostlinkedcategories]]


== Notes ==
<references/>

[[Category:Wikipedia categorization| ]]

{{Wikipedia policies and guidelines}}

[[als:Wikipedia:Kategorien]]
[[ar:ويكيبيديا:تصنيف]]
[[bn:উইকিপিডিয়া:বিষয়শ্রেণীকরণ]]
[[be-x-old:Вікіпэдыя:Катэгорыя]]
[[bg:Уикипедия:Категории]]
[[ca:Viquipèdia:Categorització]]
[[ceb:Wikipedia:Kategorisasyon]]
[[cs:Wikipedie:Kategorizace]]
[[de:Wikipedia:Kategorien]]
[[el:Βικιπαίδεια:Κατηγοριοποίηση]]
[[es:Wikipedia:Categorización]]
[[eo:Vikipedio:Kategorioj]]
[[fa:ویکی‌پدیا:رده‌بندی]]
[[gu:વિકિપીડિયા:શ્રેણી]]
[[ko:위키백과:분류]]
[[hr:Wikipedija:Kategorije]]
[[it:Wikipedia:Discussione/Categorie]]
[[he:ויקיפדיה:קטגוריה]]
[[ka:ვიკიპედია:კატეგორიზაცია]]
[[hu:Wikipédia:Kategóriák]]
[[mk:Помош:Категоризација]]
[[ml:വിക്കിപീഡിയ:വര്‍ഗ്ഗീകരണം]]
[[ms:Wikipedia:Kategori]]
[[ja:Wikipedia:カテゴリの方針]]
[[no:Hjelp:Kategorier]]
[[pl:Wikipedia:Kategoryzacja]]
[[pt:Wikipedia:Categorização]]
[[ro:Wikipedia:Categorisire]]
[[ru:Википедия:Категоризация]]
[[sl:Wikipedija:Kategorizacija]]
[[sr:Википедија:Категоризација]]
[[fi:Wikipedia:Luokittelu]]
[[sv:Wikipedia:Strukturering]]
[[th:วิธีใช้:การจัดหมวดหมู่]]
[[uk:Вікіпедія:Категоризація]]
[[vi:Wikipedia:Thể loại]]
[[yi:װיקיפּעדיע:קאטעגאריזאציע]]
[[zh:Wikipedia:頁面分類]]