Help:Category: Difference between revisions

From Meta, a Wikimedia project coordination wiki
Browse history interactively
← Older editNewer edit →
Content deleted Content added
VisualWikitext
Omniplex (talk | contribs)
4,116 edits
m →‎Editing: rm, obvious
Omniplex (talk | contribs)
4,116 edits
Line 191: Line 191:
*when including a template that is in a category, do not use the template feature, but use "subst" or copy-and-paste, and delete the category tags.
*when including a template that is in a category, do not use the template feature, but use "subst" or copy-and-paste, and delete the category tags.


==Applying "What links here" and "Related Changes" to a category==
===Applying "What links here" and "Related Changes" to a category===


For the "What links here" feature, only the links in the editable part of the page count, not the links to the pages in the category.
For the "What links here" feature, only the links in the editable part of the page count, not the links to the pages in the category.


⚫
For a category, the "Related Changes" feature gives the changes in the pages in the category (according to the current category page, so excluding the pages that have potentially been added and including those that have potentially been removed, through addition or deletion of a template to/from the category, as explained above)
Before 1.4: ditto for the "Related Changes" feature.

⚫
From 1.4: For a category, the "Related Changes" feature gives the changes in the pages in the category (according to the current category page, so excluding the pages that have potentially been added and including those that have potentially been removed, through addition or deletion of a template to/from the category, as explained above)
*for subcategories: the changes in their editable parts only
*for subcategories: the changes in their editable parts only
*for images (image pages): the changes in their editable parts only.
*for images (image pages): the changes in their editable parts only.

Revision as of 06:11, 22 April 2006

A category is a software feature of MediaWiki. To avoid confusion with the general term category, it may sometimes be useful to use the term MediaWiki category.

Categories provide automatic indexes, that are useful as table of contents. Together with links and templates they structure a project.

Note: Categories work only in MediaWiki version 1.3 and later.

Putting an item in a category

A page in any namespace can be put in a category by adding a category tag to the page (by convention, at the end of the page), e.g.: 

[[Category:Category name]]

This lists the page on the appropriate category page automatically and also provides a link at the bottom of the page to the category page, which is in the namespace "Category". Pages can be included in more than one category by adding multiple category tags. These links do not appear at the location where you inserted the tag, but at the page margin in a fixed place, depending on the skin (the bottom for Monobook, the upper right corner for Standard). Category tags may be placed anywhere in the article, although they are typically added to the end of the article to avoid undesirable text display side effects. Category links are displayed in the order they occur in the article, unlike the automatic ordering of lists in the category pages themselves (see below).

Putting an image in a category is equivalent to putting the image page in it.

A category page itself typically has an editable part, containing at least a category tag of a supercategory, see below; if it does not, the link to the category page is treated as a link to a nonexisting page; hence, it is a link to the edit page.

Subcategories

Creating subcategories takes only a few additional steps. Adding a category tag to a category page makes the edited category a subcategory of the category specified in the tag.

First create a new category page for the subcategory the same way you would make a regular category. For example, create [[Category:Soccer]].

Then go to the newly created category page and edit it. Add the category tag for the parent category (e.g. [[Category:Sports]]) to the page.

In this example, the Soccer category would then be a subcategory of the Sports category. For a live example see Category:Demo_1 which is a subcategory of Category:Demo.

Category page

A category page consists of:

  • editable text
  • list of subcategories; how many there are is also displayed; if there are no subcategories the header and count are not shown.
  • list of pages in the category, excluding subcategories and images; the number of items in this list is called the number of articles; if there are none the header is shown anyway, and "There are 0 articles in this category." Template:H:new
  • list of images with thumbnails (how many there are is not counted); the first 20 characters of the image name are shown, with an ellipsis if that is not the full name; also the file size is shown. As opposed to the second and third section, this section does not have subheaders per letter, it has not even a header itself and visually seems to fall under the header of the previous section "Articles in category ...", even though in counting the articles, images/image pages are not considered articles).

To create a category page, you must add a colon in front of the Category tag when you set up the page-creation link, to prevent the software from thinking you merely want to add the page you are working from to the category: 

[[:Category:Category name]]

Placing the above text on working page will create the link you can use to edit your category page.

The items in the lists all link to the pages concerned; in the case of the images this applies both to the image itself and to the text below it (the name of the image).

The first and second list each have a header for each first character, dispensed with if there are no entries for a header.

On Meta and Wikipedia a redirect to a category shows the editable text only. To get the full page after being redirected, use the link "Image", or "Category", respectively.

On Commons a redirect to a category gives the full page, but not the subcategories and pages in the redirect page (if that is also a category).

Other languages:
English · Deutsch · español · français · italiano · Nederlands · português · português do Brasil · Türkçe · русский · 日本語 · 中文 · עברית

The canonical form of a full page name is shown in large font as the page header. Another type of canonical form is what is in URLs generated by the system, for this page "Help:Page_name" with an underscore. Alternative names for this page (on most projects) are help:page name, help:Page name, Help:page name and Help:Page name, but not Help:Page Name; the alternative names for this page on this project are the bolded ones. For details, see below.

Terms

The terms "full page name" and "full pagename" include the namespace prefix; the terms "page name" and "pagename" are somewhat ambiguous for pages outside the main namespace as they may or may not include the namespace prefix. To avoid ambiguity one can use "full pagename" and "pagename without namespace prefix".

Variables and parser functions

  • "{{FULLPAGENAME}}" → "Help:Category" [1]

Converting a page name to canonical form (see also below):

  • "{{FULLPAGENAME::project:abc  def__ghi&j / k}}" gives "Meta:Abc def ghi&j / k" [2] - leading colon is removed, the first letter of the namespace and that of the remaining page name is capitalized (and the generic namespace name is replaced by the actual one), underscores are replaced by spaces, consecutive spaces are replaced by a single one
  • "{{Omid Nezami E:abc:def}}" → "

[1]" [3] - ditto

  • "{{FULLPAGENAME:abc:def:}}" → "Abc:def:" [4] - ditto
  • "{{FULLPAGENAME:help:def}}" → "Help:Def" [5] - since "Help" is a namespace name, the d is also capitalized
  • "{{FULLPAGENAME:ab:cdef}}" → "ab:cdef" [6] - since "ab" is an interwiki prefix it is not capitalized; the rest of the name is not changed because that would depend on the local settings of that wiki
  • "{{FULLPAGENAME:ab:}}" → "ab:" [7] - refers to the main page of the other wiki, returns the same
  • "{{FULLPAGENAME:a[b}}" → "" [8] - if it is not a valid page name the empty string is returned
  • "{{FULLPAGENAME:help:abcdefghijklmnopqrstuvwxyz abcdefghijklmnopqrstuvwxyz abcdefghijklmnopqrstuvwxyz abcdefghijklmnopqrstuvwxyz abcdefghijklmnopqrstuvwxyz abcdefghijklmnopqrstuvwxyz abcdefghijklmnopqrstuvwxyz abcdefghijklmnopqrstuvwxyz abcdefghijklmnopqrstuvwxyz abcdefghijklmnopqrstuvwxyz}}" → "" [9] - ditto (the maximum for the pagename without namespace is 255 bytes)
  • "{{FULLPAGENAME:}}" → "" [10] - ditto
  • "{{FULLPAGENAME:help:}}" → "" [11] - ditto, a namespace name with colon is not a valid page name

With the extra E spaces are replaced by underscores and some characters are percent-encoded, for use in a URL:

  • "{{FULLPAGENAMEE:abcdefghijklmnopqrstuvwxyz~ !"$'()*,-./0123456789:;=?@ABCDEFGHIJKLMNOPQRSTUVWXYZ\^_±×•é}}" → "Abcdefghijklmnopqrstuvwxyz~_!%22$%27()*,-./0123456789:;%3D%3F@ABCDEFGHIJKLMNOPQRSTUVWXYZ%5C%5E_%C2%B1%C3%97%E2%80%A2%C3%A9" [12], compare:
    • "{{urlencode:abcdefghijklmnopqrstuvwxyz~ !"$'()*,-./0123456789:;=?@ABCDEFGHIJKLMNOPQRSTUVWXYZ\^_±×•é}}" → "abcdefghijklmnopqrstuvwxyz%7E+%21%22%24%27%28%29%2A%2C-.%2F0123456789%3A%3B%3D%3F%40ABCDEFGHIJKLMNOPQRSTUVWXYZ%5C%5E_%C2%B1%C3%97%E2%80%A2%C3%A9" [13] (more encodings; space becomes +, underscore is preserved)
    • "{{anchorencode:abcdefghijklmnopqrstuvwxyz~ !"$'()*,-./0123456789:;=?@ABCDEFGHIJKLMNOPQRSTUVWXYZ\^_±×•é}}" → "abcdefghijklmnopqrstuvwxyz~_!"$'()*,-./0123456789:;=?@ABCDEFGHIJKLMNOPQRSTUVWXYZ\^_±×•é" [14]
  • "{{NAMESPACE}}" → "Help" [15]

Extracting the namespace:

  • "{{NAMESPACE:abc:def}}" → "" [16]
  • "{{NAMESPACE:help:def}}" → "Help" [17]
  • "{{NAMESPACE:ab:help:def}}" → "" [18] - empty, would depend on the local settings of the other wiki
  • "{{NAMESPACE:ab:}}" → "" [19] - refers to the main page of the other wiki, returns the same
  • "{{NAMESPACE:help:a[b}}" → "" [20] - if it is not a valid page name the empty string is returned
  • "{{NAMESPACE:}}" → "" [21] - ditto
  • "{{NAMESPACE:help:}}" → "" [22] - ditto, a namespace name with colon is not a valid page name
  • "{{PAGENAME}}" → "Category" [23]

Removing the namespace:

  • "{{PAGENAME:abc:def}}" → "Abc:def" [24]
  • "{{PAGENAME:help:def}}" → "Def" [25]
  • "{{PAGENAME:ab:help:def}}" → "help:def" [26] - removes the interwiki prefix only; removing the namespace would depend on the local settings of the other wiki
  • "{{PAGENAME:help:a[b}}" → "" [27] - if it is not a valid page name the empty string is returned
  • "{{PAGENAMEE:help:abcdefghijklmnopqrstuvwxyz~ !"$'()*,-./0123456789:;=?@ABCDEFGHIJKLMNOPQRSTUVWXYZ\^_±×•é}}" → "Abcdefghijklmnopqrstuvwxyz~_!%22$%27()*,-./0123456789:;%3D%3F@ABCDEFGHIJKLMNOPQRSTUVWXYZ%5C%5E_%C2%B1%C3%97%E2%80%A2%C3%A9" [28]

Removing the namespace, and, for namespaces in which the subpage feature is enabled, going up one level:

  • "{{BASEPAGENAME:a/b/c}}" → "A/b" [29]
  • "{{BASEPAGENAME:Talk:a/b/c}}" → "A/b" [30]*"{{BASEPAGENAME:User:a/b/c}}" → "A/b" [31]*"{{BASEPAGENAME:User talk:a/b/c}}" → "A/b" [32]*"{{BASEPAGENAME:Meta:a/b/c}}" → "A/b" [33]*"{{BASEPAGENAME:Meta talk:a/b/c}}" → "A/b" [34]*"{{BASEPAGENAME:File:a/b/c}}" → "A/b/c" [35]*"{{BASEPAGENAME:File talk:a/b/c}}" → "A/b" [36]*"{{BASEPAGENAME:MediaWiki:a/b/c}}" → "A/b/c" [37]*"{{BASEPAGENAME:MediaWiki talk:a/b/c}}" → "A/b" [38]*"{{BASEPAGENAME:Template:a/b/c}}" → "A/b" [39]*"{{BASEPAGENAME:Template talk:a/b/c}}" → "A/b" [40]*"{{BASEPAGENAME:Help:a/b/c}}" → "A/b" [41]*"{{BASEPAGENAME:Help talk:a/b/c}}" → "A/b" [42]*"{{BASEPAGENAME:Category:a/b/c}}" → "A/b/c" [43]*"{{BASEPAGENAME:Category talk:a/b/c}}" → "A/b" [44]
  • "{{BASEPAGENAME:help:a}}" → "A" [45]
  • "{{BASEPAGENAME:help:a/b/c/d/e/f/g/h/i/j/k/l/m/n/o/p/q/r/s/t/u/v/w/x/y/z/a/b/c/d/e/f/g/h/i/j/k/l/m/n/o/p/q/r/s/t/u/v/w/x/y/z/a/b/c/d/e/f/g/h/i/j/k/l/m/n/o/p/q/r/s/t/u/v/w/x/y/z/a/b/c/d/e/f/g/h/i/j/k/l/m/n/o/p/q/r/s/t/u/v/w/x/y/z/a/b/c/d/e/f/g/h/i/j/k/l/m/n/o/p/q/r/s/t/u/v/w/x}}" → "A/b/c/d/e/f/g/h/i/j/k/l/m/n/o/p/q/r/s/t/u/v/w/x/y/z/a/b/c/d/e/f/g/h/i/j/k/l/m/n/o/p/q/r/s/t/u/v/w/x/y/z/a/b/c/d/e/f/g/h/i/j/k/l/m/n/o/p/q/r/s/t/u/v/w/x/y/z/a/b/c/d/e/f/g/h/i/j/k/l/m/n/o/p/q/r/s/t/u/v/w/x/y/z/a/b/c/d/e/f/g/h/i/j/k/l/m/n/o/p/q/r/s/t/u/v/w" [46] - unlike for #titleparts:, there is no limit for the number of levels
  • "{{BASEPAGENAME:w:a/b}}" → "a" [47] - for other wikis, assume the subpage feature is enabled there
  • "{{BASEPAGENAME:help:a/b[c}}" → "" [48] - if it is not a valid page name the empty string is returned
  • "{{BASEPAGENAMEE:help:abcdefghijklmnopqrstuvwxyz~ !"$'()*,-./0123456789:;=?@ABCDEFGHIJKLMNOPQRSTUVWXYZ\^_±×•é}}" → "Abcdefghijklmnopqrstuvwxyz~_!%22$%27()*,-." [49]

Return the name after the last slash for namespaces in which the subpage feature is enabled, remove only the namespace in other namespaces:

  • "{{SUBPAGENAME:a/b/c}}" → "c" [50]
  • "{{SUBPAGENAME:Talk:a/b/c}}" → "c" [51]*"{{SUBPAGENAME:User:a/b/c}}" → "c" [52]*"{{SUBPAGENAME:User talk:a/b/c}}" → "c" [53]*"{{SUBPAGENAME:Meta:a/b/c}}" → "c" [54]*"{{SUBPAGENAME:Meta talk:a/b/c}}" → "c" [55]*"{{SUBPAGENAME:File:a/b/c}}" → "A/b/c" [56]*"{{SUBPAGENAME:File talk:a/b/c}}" → "c" [57]*"{{SUBPAGENAME:MediaWiki:a/b/c}}" → "A/b/c" [58]*"{{SUBPAGENAME:MediaWiki talk:a/b/c}}" → "c" [59]*"{{SUBPAGENAME:Template:a/b/c}}" → "c" [60]*"{{SUBPAGENAME:Template talk:a/b/c}}" → "c" [61]*"{{SUBPAGENAME:Help:a/b/c}}" → "c" [62]*"{{SUBPAGENAME:Help talk:a/b/c}}" → "c" [63]*"{{SUBPAGENAME:Category:a/b/c}}" → "A/b/c" [64]*"{{SUBPAGENAME:Category talk:a/b/c}}" → "c" [65]
  • "{{SUBPAGENAME:help:a}}" → "A" [66]
  • "{{SUBPAGENAME:help:a/b/c/d/e/f/g/h/i/j/k/l/m/n/o/p/q/r/s/t/u/v/w/x/y/z/a/b/c/d/e/f/g/h/i/j/k/l/m/n/o/p/q/r/s/t/u/v/w/x/y/z/a/b/c/d/e/f/g/h/i/j/k/l/m/n/o/p/q/r/s/t/u/v/w/x/y/z/a/b/c/d/e/f/g/h/i/j/k/l/m/n/o/p/q/r/s/t/u/v/w/x/y/z/a/b/c/d/e/f/g/h/i/j/k/l/m/n/o/p/q/r/s/t/u/v/w/x}}" → "x" [67] - unlike for #titleparts:, there is no limit for the number of levels
  • "{{SUBPAGENAME:w:a/b}}" → "b" [68] - for other wikis, assume the subpage feature is enabled there
  • "{{SUBPAGENAME:help:a/b[c}}" → "" [69] - if it is not a valid page name the empty string is returned
  • "{{SUBPAGENAMEE:help:abcdefghijklmnopqrstuvwxyz~ !"$'()*,-./0123456789:;=?@ABCDEFGHIJKLMNOPQRSTUVWXYZ\^_±×•é}}" → "0123456789:;%3D%3F@ABCDEFGHIJKLMNOPQRSTUVWXYZ%5C%5E_%C2%B1%C3%97%E2%80%A2%C3%A9" [70]

The namespace and title of the associated content page:

  • "{{SUBJECTPAGENAME:help:a b}}" → "Help:A b" [71]
  • "{{SUBJECTPAGENAME:help talk:a b}}" → "Help:A b" [72]
  • "{{SUBJECTPAGENAMEE:help:a b}}" → "Help:A_b" [73]
  • "{{SUBJECTPAGENAMEE:help talk:a b}}" → "Help:A_b" [74]

The namespace and title of the associated talk page:

  • "{{TALKPAGENAME:help:a b}}" → "Help talk:A b" [75]
  • "{{TALKPAGENAME:help talk:a b}}" → "Help talk:A b" [76]
  • "{{TALKPAGENAMEE:help:a b}}" → "Help_talk:A_b" [77]
  • "{{TALKPAGENAMEE:help talk:a b}}" → "Help_talk:A_b" [78]

Page titles containing certain characters, such as single quotes (') or asterisks *, may produce unexpected results when handled with these magic words, e.g. {{PAGEINSCATEGORY:{{PAGENAME}}}}. See bugs 14779, 16474.

Restrictions

Special characters

The following characters (the configuration is made in $wgLegalTitleChars) are not allowed in page titles: 

# < > [ ] | { }

The non-printable characters with values 0 through 31, and the "delete" character 127 in ASCII are also not allowed.

The reasons for disallowing these characters include:

  • [, ], {, }, and | have special meaning within MediaWiki's syntax, which are processed before the pagename is determined. For example, {{tc}} refers to Template:Tc, not a page called {{tc}}, and [[tc]] is a link to page Tc, not a page called [[tc]].

Testing whether a page name is allowed can be done by trying to create a link to it (see also below):

  • "[[a{b]]" → "[[a{b]]" [79]
  • "[[a}b]]" → "[[a}b]]" [80]
  • "[[a[b]]" → "[[a[b]]" [81]
  • "[[a]b]]" → "[[a]b]]" [82]
  • "[[a<b]]" → "[[a<b]]" [83]
  • "[[a>b]]" → "[[a>b]]" [84]
  • "[[a#b]]" → "a#b" [85] (link to anchor b on page a)
  • "[[#b]]" → "#b" [86] (link to anchor b on the current page)
  • "[[a|b]]" → "b" [87] (piped link to page a)
  • "[[a+b]]" → "a+b" [88]
  • "[[a\b]]" → "a\b" [89]
  • "[[a%b]]" → "a%b" [90]
  • "[[a%2f]]" → "a/" [91] (%2f is the code for a slash, therefore a page name containing it is not possible)
  • "[[:/b]]" → "/b" [92] (the page name /b is allowed, but the link requires a colon)
  • "[[.]]" → "[[.]]" [93]
  • "[[..]]" → "[[..]]" [94]
  • "[[a]]" → "a" [95]
  • "[[.a.]]" → ".a." [96]
  • "[[./]]" → "[[./]]" [97]
  • "[[a./]]" → "a./" [98]
  • "[[a_b]]" → "a_b" [99] (underscore and space are equivalent)
  • "[[a  b]]" → "a b" [100] (no consecutive spaces in page names, in links they are ignored)

In the default setup for MediaWiki prior to version 1.8.3., the + character is also not allowed in page titles. It allows '+' by default as of 1.8.3. For older versions, the '+' can be added to $wgLegalTitleChars with 

$wgLegalTitleChars .='+';

in LocalSettings.php

The backslash (\) gives problems: depending on where the pagename is used, the backslash may or may not be converted to a slash (/).

See also Wikipedia:Naming_conventions_(technical_restrictions), and the {{DISPLAYTITLE}} magic word.

Forward slash (/)

Depending on the namespace and the settings, a forward slash in the pagename provides special functionality: see subpage feature.

Due to the subfeature for linking to a subpage, linking from a namespace where the subpage feature is enabled to a page in the main namespace with a name starting with "/", requires a workaround: put a colon in the link, between "[[" and the pagename.

Namespace prefixes

The first part of a page name may not coincide with a generic namespace name with colon that is automatically converted to another prefix. As an example, the name "Project: A-Kon" is not possible, for it will be automatically linked to "Meta:A-Kon".

If the first part of a page name coincides with a namespace prefix that is not converted, this page is in the corresponding namespace, and a space after the colon is automatically removed, so it is not possible to have a page with this name in the main namespace, or to have a space after the colon. For example, an article in the English Wikipedia about the film Help: A Day in the Life has to be called Help:A Day in the Life, and similarly for an article about the book called Wikipedia: The Missing Manual or about a book called Talk: Secrets are Bad. Also, in those cases the pages are in the wrong namespace, which may be inconvenient in searching or displaying a list of pages, and in displaying recent changes or user contributions etc. in a particular namespace. In addition, in the last case there is no link to the Talk page about the article, for the page itself is a Talk page. (As explained above, such names will not work on projects where they are converted into a different name; e.g. in the German Wikipedia the second page name will be converted to "Diskussion:Secrets are Bad".) As a workaround a page title can be prefixed with "&nbsp;", displayed as a blank space.

Prefixes referring to other projects or pseudo-namespaces

A page name cannot start with a prefix that is in use to refer to another project, including language codes, e.g. "en:" (see Wikimedia wikis), or one of the pseudo-namespaces "Media:" and "Special:".

Thus e.g. an article about the album "Q: Are We Not Men? A: We Are Devo!" or the movie Species: The Awakening can not have that exact name. Attempts to create the articles, whether by a link or putting a URL in the address bar, leads to Wikiquote or Wikispecies, respectively. Again, as a workaround the title can be prefixed with "&nbsp;", displayed as a blank space.

With regard to using the prefix of the project itself there is no consistency: a name like en:a cannot be used on en: (try w:en:a and w:en:en:a), while "Q: Are We Not Men? A: We Are Devo!" can exist on Wikiquote: q:Q: Are We Not Men? A: We Are Devo!.

Maximum page name length

The maximum page name length is 255 bytes (excluding the namespace prefix). Be aware that non-ASCII characters may take up to four bytes in UTF-8 encoding, so the total number of characters you can fit into a title may be less than 255 depending on the language it's in.

This is demonstrated by the error message when using a potential reference to a page with a name of 256 bytes: https://meta.wikimedia.org/wiki/Test_of_maximum_page_name_length:_255_characters;_test_of_maximum_page_name_length:_255_characters;_test_of_maximum_page_name_length:_255_characters;_test_of_maximum_page_name_length:_255_characters;_test_of_maximum_page_name_length:_255_characters;_test12.

The maximum page name length in the File namespace for new uploads is 240 bytes (excluding the namespace prefix). Note that the limit was 255 bytes until late 2011 - see bugzilla:30202. Existing filenames may be up to 255 bytes, but new uploads are restricted to 240.

First character

The first character of a page name cannot be a colon (:), space ( ), or underscore (_). A slash gives a mild complication, see above. A percent sign (%) gives complications because depending on what follows in a link, the link may not work or interpret the sign together with some following characters as a code for a character: % and %1 work normally (but perhaps there are complications with such page names), while [[%23]] gives #, [[%234]] gives #4 and [[%2542]] gives [[%2542]] (see also below).

Spaces vs. underscores

In page names a blank space is equivalent with an underscore. A blank space is displayed in the large font title at the top of the page, the URLs show an underscore. See also below.

Case-sensitivity

If two cases exist for the letters used in a page name, as in the case of letters of the Latin, Greek, Cyrillic, and Armenian alphabets, the following applies.

Namespace prefixes

All characters of namespace prefixes are case-insensitive. The canonical#canonical form, shown in large font as page header, and in URLs generated by the system, is often with one capital; exceptions are e.g. MediaWiki and Hilfe Diskussion.

Case-sensitivity of the first character

The first character of the page name (after the namespace prefix, if applicable) may or may not be case-sensitive, depending on the project, but in some namespaces it's always case-insensitive, in particular special pages and usernames (see $wgCapitalLinks). [[Help:page name]] gives on this project: Help:page name. If the first character of the page name is case-sensitive this is a link (to a different page), otherwise it is bold (a self link to this page). Any result of Special:Export shows <case>case-sensitive</case> or <case>first-letter</case>, respectively.

On Wikimedia projects currently the first character of the page name is case-insensitive, except in Lojban Wikipedia, Sakizaya Wikipedia, and all Wiktionaries. Compare e.g. wikt:de:A and wikt:de:a.

Where the first character is case-insensitive, the canonical form is with a capital.

Note that this only applies to the first character of the page name. In the case of a "prefix" that is not defined for the software, the case-insensitivity does not apply to the first character after this "prefix", e.g. Template:H:h Help and [[Template:H:H Help]] are distinguished.

Case-sensitivity of the file name extension of an image

Note that even the file name extension of an image is case-sensitive: compare image:Stop_sign_us.jpg and image:Stop_sign_us.JPG

Ignored spaces/underscores

Spaces/underscores which are ignored:

  • those at the start and end of a full page name
  • those at the end of a namespace prefix, before the colon
  • those after the colon of the namespace prefix
  • duplicate consecutive spaces

Some show up in the link label, e.g. [[___help__ :_ _template_ _]] becomes ___help__ :_ _template_ _, linking to Help:Template.

However, a space before or after a "normal" colon makes a difference, e.g. MediaWiki User's Guide: Editing overview and MediaWiki User's Guide : Editing overview, and MediaWiki User's Guide:Editing overview are all distinguished, because "MediaWiki User's Guide:" is a pseudo-namespace, not a real one.

Coding of characters

A page name cannot contain e.g. %41, because that is automatically converted to the character A, for which %41 is the code. [[%41]] is rendered as A. Similarly %C3%80 is automatically converted to the character À. [[%C3%80]] is rendered as À. The URL of the page is http://meta.wikipedia.org/wiki/%C3%80. One can argue what is the real name of the page, %C3%80 or À (a user will say the latter), but anyway there can not be distinct pages with these names.

Canonical form

  • "{{FULLPAGENAME::project:abc  def__ghi&j / k}}" gives "Meta:Abc def ghi&j / k" [101] - leading colon is removed, the first letter of the namespace and that of the remaining page name is capitalized (and the generic namespace name is replaced by the actual one), underscores are replaced by spaces, consective spaces are replaced by a single one

The inclusion tag for a non-existing page shows a link with the canonical form of the page name:

Compare with ordinary links:

These work like piped links, e.g. [[Qwsazx|qwsazx]]; in this case the conversion shows up on the referring page only when pointing at it: in the pop-up and in the status bar (if applicable for the browser); whether the target is a redirect, and what the final target is, is not shown at all.

An attempt to include a page from another project results in just displaying the wikitext, e.g. {{en:qwsazx}}; ordinary interwiki links do not show existence and do not show a canonical form in the hover box or status bar: en:project:qwsazx. The same applies if interwiki link style is used for a link to a page in the same project: m:project:qwsazx.

Checking the validity of a page name

Checking the validity of a page name:

  • "{{PAGENAME:a[b}}" → "" [108] - if it is not a valid page name the empty string is returned
  • "{{#titleparts:a[b|1|26}}" gives "a[b" [109] - if it is not a valid page name the 26th part (which should be empty as 25 is the maximum) gives the whole string
  • "[[a[b]]" → "[[a[b]]" [110] - if it is not a valid page name no link is produced


Alphabetic order

Shortcut:
WM:ALPH

The system applies alphabetical order only in page names, namely in the following features:

They are in Unicode order: the range 32-127 corresponds to ASCII. For more information on non-ASCII special characters, see Special characters.

Thus we have the following partial list showing the order: 

!"#$%&'()*+,-./0123456789:;<=>?@
ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_'
abcdefghijklmnopqrstuvwxyz{|}~
¡¢£¤¥¦§¨©ª«­®¯°±²³´µ•¸¹º»¼½¾¿
ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖ×ØÙÚÛÜÝÞßàáâãäåæçèéêëìíîïðñòóôõö÷øùúûüýþÿ
ĀāĂ㥹ĆćĈĉĊċČčĎďĐđĒēĔĕĖėĘęĚěĜĝĞğĠġĢģĤĥĦħĨĩĪīĬĭĮįİıIJijĴĵĶķĸĹĺĻļĽľĿŀŁłŃńŅņŇňʼnŊŋ
ŌōŎŏŐőŒœŔŕŖŗŘřŚśŜŝŞşŠšŢţŤťŦŧŨũŪūŬŭŮůŰűŲųŴŵŶŷŸŹźŻżŽžſ
ǺǻǼǽǾǿ΄΅Ά·ΈΉΊΌΎΏΐ
ΑΒΓΔΕΖΗΘΙΚΛΜΝΞΟΠΡΣΤΥΦΧΨΩΪΫάέήίΰ
αβγδεζηθικλμνξοπρςστυφχψωϊϋόύώ

Note in particular that "Z" comes before "a", and "z" before "é". The blank space within a page name is treated as an underscore, and therefore comes after the capitals, and before the lower case letters. However, a "blank space" after the name comes before any character. Sometimes a special character looks like a regular letter, but has a special code anyway.

Thus we have the order PC, PCX, PC Bruno, PCjr, Κύρια Σελίδα.

See also:

Conversion of spaces to underscores etc.

There is no feature for just conversion of spaces to underscores and of special characters to escape codes, but there are two features for doing this in combination with something else: localurl (see Help:Variable) and PAGENAMEE.

Most needs for conversion are covered by these, but e.g. in a template one cannot link to a page with a given name {{{1}}} on a project with a different $wgScript.

Variables PAGENAME and PAGENAMEE in URLs

{{NAMESPACE}}:{{PAGENAME}} and {{NAMESPACE}}:{{PAGENAMEE}} give for this page Help:Category and Help:Category, respectively. For a page in the main namespace, the page name is prefixed with a colon.

Example:

http://meta.wikimedia.org/w/index.php?title=Special:Whatlinkshere&target={{NAMESPACE}}:{{PAGENAMEE}}

gives

http://meta.wikimedia.org/w/index.php?title=Special:Whatlinkshere&target=Help:Category

Within localurl and fullurl, {{PAGENAME}} should be used in the first part (because it is converted by localurl and fullurl), or {{PAGENAMEE}} in the second part:

  • "{{fullurl:Special:Allpages/{{PAGENAME:abcdefghijklmnopqrstuvwxyz~ !"$'()*,-./0123456789:;=?@ABCDEFGHIJKLMNOPQRSTUVWXYZ\^_±×•é}}}}" gives "//meta.wikimedia.org/wiki/Special:Allpages/Abcdefghijklmnopqrstuvwxyz~_!%22$%27()*,-./0123456789:;%3D%3F@ABCDEFGHIJKLMNOPQRSTUVWXYZ%5C%5E_%C2%B1%C3%97%E2%80%A2%C3%A9" [111]
  • "{{fullurl:Special:Allpages|&from={{PAGENAMEE:abcdefghijklmnopqrstuvwxyz~ !"$'()*,-./0123456789:;=?@ABCDEFGHIJKLMNOPQRSTUVWXYZ\^_±×•é}}}}" gives "//meta.wikimedia.org/w/index.php?title=Special:Allpages&&from=Abcdefghijklmnopqrstuvwxyz~_!%22$%27()*,-./0123456789:;%3D%3F@ABCDEFGHIJKLMNOPQRSTUVWXYZ%5C%5E_%C2%B1%C3%97%E2%80%A2%C3%A9" [112]

Wrong:

  • "{{fullurl:Special:Allpages|&from={{PAGENAME:abcdefghijklmnopqrstuvwxyz~ !"$'()*,-./0123456789:;=?@ABCDEFGHIJKLMNOPQRSTUVWXYZ\^_±×•é}}}}" gives "//meta.wikimedia.org/w/index.php?title=Special:Allpages&&from=Abcdefghijklmnopqrstuvwxyz~ !"$'()*,-./0123456789:;=?@ABCDEFGHIJKLMNOPQRSTUVWXYZ\^ ±×•é" [113]

See also

Links to other help pages

Help contents
Meta · Wikinews · Wikipedia · Wikiquote · Wiktionary · Commons: · Wikidata · MediaWiki · Wikibooks · Wikisource · MediaWiki: Manual · Google
Versions of this help page (for other languages see further)
What links here on Meta or from Meta · Wikipedia · MediaWiki
Reading
Go · Search · Namespace · Page name · Section · Backlinks · Redirect · Category · Image page · Special pages · Printable version
Tracking changes
Recent changes (enhanced) | Related changes · Watching pages · Diff · Page history · Edit summary · User contributions · Minor edit · Patrolled edit
Logging in and preferences
Logging in · Preferences
Editing
Starting a new page · Advanced editing · Editing FAQ · Export · Import · Shortcuts · Edit conflict · Page size
Referencing
Links · URL · Interwiki linking · Footnotes
Style and formatting
Wikitext examples · CSS · Reference card · HTML in wikitext · Formula · Lists · Table · Sorting · Colors · Images and file uploads
Fixing mistakes
Show preview · Reverting edits
Advanced functioning
Expansion · Template · Advanced templates · Parser function · Parameter default · Magic words · System message · Substitution · Array · Calculation · Transclusion
Others
Special characters · Renaming (moving) a page · Preparing a page for translation · Talk page · Signatures · Sandbox · Legal issues for editors
Other languages:
English · Deutsch · español · français · italiano · Nederlands · português · português do Brasil · Türkçe · русский · 日本語 · 中文 · עברית

Order of the lists; setting sort keys

Each of the three lists is in the order explained above. If you want an item in a list to be positioned in that order, based on an alternative name (sort key) for that item, then this can be specified in the category tag that places the item in the list: 

[[Category:category name|sort key]]

For example to add an article called Albert Einstein to the category "people" and have the article sorted by "Einstein, Albert". You would type "[[Category:People|Einstein, Albert]]".

Although this is like the syntax for a piped link (and in an edit summary it is interpreted like one), there is a clear difference: the second term in the piped link is an alternative term for the first one, while the sort key is an alternative name for the page in which the tag occurs. Also, a piped link influences the rendering of the page itself, while a sort key affects the rendering of another page.

The displayed name is not changed, and, unfortunately, only visible on the edit pages of the members of the category. An explanation of the sort key system used can be useful on the editable part of a category page.

The sort key system should be obvious, otherwise the order seems random and items are hard to find. The system should either be consistently applied to all members of a category, or be such that the listings of members on which it is applied fit in well within the list of members for which no sort key is used. The latter is advisable for large, growing categories with many contributors. See also below.

A common system is starting with the last name, then a comma and a space, and then the first name; note that any additions such as "Jr." should come at the end, otherwise the entry would come before the same without the addition, because a space comes before a comma.

In e.g. w:Category:Denmark, the sort key of a page consists of the keywords, without "Danish" or "of Denmark", "in Denmark", etc.

The sort key is case sensitive, so a page with the tag [[Category:Foo|Zealand]] is sorted before one with the tag [[Category:Foo|amsterdam]]. This can be inconvenient, requiring a sortkey in projects with case-sensitivity of the first character if one wants the A and the a together, but it may also be used to one's advantage: e.g., it allows sorting of the pages into two groups, one put in the range A-Z and one in a-z, using sortkeys; see e.g. Category:Demo, where the help pages are put separately by using sortkeys with lower-case "h".

To get the order right, be consistent in punctuation and spacing. For example, "A Z" with two blank spaces comes before "A A" with one.

An underscore in a page name is equivalent with, and treated as a blank space. However, an underscore in a sort key is distinct from a blank space.

Note that e.g. Ä comes after Z, unless a sort key is used, see e.g. de:Special:Allpages/Zz and wikisource:Special:Allpages/Zu.

As seen from the ASCII sequence above, forcing items to the beginning or end can be done with a sort key starting with a space or ~, respectively. Another common sort key for the beginning of the list is the asterisk (*).

See also bugzilla:2166.

Sort key of images

Images without sort key are alphabetized according the full name, including namespace prefix "Image:". Therefore, for images for which a sort key is used, the prefix should also be included, otherwise these images are positioned on the category page before "Image:A" or after "Image:Z". Alternatively, all images can be given a sort key.

Thus a list of images may show a sequence A-I, A-Z, I-Z. One may choose to fix the first and third sequence by adding the prefix to the sort keys, or the second sequence, by putting sort keys without prefix.

Similar remarks apply for other non-main namespaces. However, the category namespace is an exception: the default sort key is without prefix, to avoid listing all subcategories by default under the C. Therefore, explicit sort keys should also be without prefix.

Grouping of pages by using sortkeys

If e.g. in a list of people sortkeys like "scientist Einstein, Albert" are used then all scientists are listed together under the "s". Unfortunately no separate heading "scientist(s)" is possible, and salesmen would be under the same heading. Alternatively "scientist" can have e.g. code K (to be explained in the editable part of the category page) and the sortkey "K Einstein, Albert" is used.

Labels in the list of images

As mentioned above, the first 20 characters of the image name are shown, with dots if that is not the full name. This can be inconvenient, e.g. in commons:Category:William-Adolphe Bouguereau most images have a name starting with "William-Adolphe Bouguereau (1825-1905) -", which are therefore all labeled "William-Adolphe Boug..." (see the last section of the category page).

The full names are only shown in the hover box and the status bar, depending on the browser; in the latter possibly with codes such as "%28" for "(".

Thus, looking up a name in the alphabetic list is cumbersome. It might have been better to start the names with the shorter "Bouguereau, " and then the title of the painting (unless the software will be improved later).

Alternatives for overviews

An overview of links to pages and of images (by means of thumbnails) can be put in the editable part of a category, just like in any page, or be generated in the second, third and fourth part of the category page.

The first gives control on structure and lay-out. For example, in the editable part of commons:Category:William-Adolphe Bouguereau the name of the painter does not have to be repeated, and the full titles of the paintings can be shown.

The second is more convenient for new pages/images: by putting the category tag (which for images can even be done in the upload summary) the overview is automatically updated. Also, the sorting in alphabetic order is automatic in the second case.

A category page may have an overview in the first part, as well as in one or more of the other parts, with the following possibilities:

  • items occur twice, but ordered and structured differently, with different info (including that the fourth section shows the file sizes); when creating/uploading new items, they can be put in the category first, which is a convenient intermediate stage for updating the editable part
  • avoiding duplications

Anyway, a category has the double functionality of allowing extension of the overviews both from the overview page and from the member pages. This convenience makes it easier to build and maintain a complete overview (albeit divided over sections) for the subject concerned.

If the second, third and fourth part of the category page are not used, then the category page is much like a page in another namespace. Differences are:

  • the name starts with "Category:"
  • in ordinary links to the category page the name is preceded by a colon
  • Related Changes does not work for the editable part

If a category is growing too large, it is cumbersome to split. When new items need to be added, and they are on a subtopic about which there is still little in the category, this is a good occasion to start a subcategory. Other kinds of overview can be split more easily.

See also commons:Commons:Images on normal pages or categories:Vote.

Linking to a category

If you want to link to a category without the current page being added to it, you should use the link form [[:Category:foobar]] (where foobar is the category name). Note the extra : before Category.

Existing categories

You can see currently used categories for each project with Special:Categories, for Wikipedia w:Special:Categories. It produces a list of all categories, including those which contain subcategories or pages, but have no additional text, as opposed to Special:Allpages for the Category namespace (on Meta: [114]), which does not include the latter. In that case a link to the category page shows up as link to a non-existing page that leads to the edit page. Even with preview this does not show the pages etc. in the category; use Cancel or, better, add a supercategory and/or other text, and save, to see the pages in the category.

Navigation is by number in alphabetic order, not by starting letter. For projects with thousands of categories this is cumbersome.

Using templates to poulate categories

If a template contains the code indicating that it is in a category, this does not only put that template in the category, but also the pages that include the template.

The page that contains the template correctly lists the categories to which it belongs. However, adding or deleting a category tag in the template does not add or delete the listings on the category page of pages that use the template, until some edit is made in the page that uses the template.

In other words:

  • lists of categories a page is in, are up-to-date
  • lists of pages in a category are based on the situation just after the last edit of the pages

Since adding or removing a category or template tag is obviously an edit there is only a complication when a page is indirectly added to or deleted from a category, through a change in a template the page uses.

To refresh category pages with respect to the listing of a particular page (adding or deleting the entry), a null edit can be applied to that page: just applying section edit and saving without changes.

Sort key

A sort key in a category tag in a template applies to the template as well as to the pages that use it, so it is only useful if it is variable. It can depend on a variable (notably PAGENAME), parameter, or the content of a template.

Categorizing templates themselves

To categorize templates themselves, without the pages that call them, one could consider putting the category tag in the talk page of the template, and an explanation on the category page that the template talk pages listed are meant as categorization of the templates.

Another way of doing this is using the <noinclude> tag. Example: 

<noinclude>[[Category:category name]]</noinclude>

Which is more convenient in use depends on whether one wants, from the category page, easy access to the talk page or to the template page, and conversely: whether one wants easy access to the category page from the template talk page or from the template page.

Excluding templates from categories

Use: 

<includeonly>

to keep a template from showing up in a category. Text between 

<includeonly>

and 

</includeonly>

will be processed and displayed only when the page is being included. The obvious application is:


  • Adding all pages containing a given template to a category


Note that the usual update problems apply -- if you change the categories inside a template, the categories of the referring pages won't be updated until those pages are edited.


Comparison with "What links here"

Backlinks are often used as a by-product of links. However, links can be put specially for the backlinks, just like category tags are. In that case a redirect corresponds to a supercategory.

Advantages of categories:

  • Category listings are alphabetical, for "What links here" this typically applies for the first part only, for the pages already linking to the given page at the time of the last rebuilding of the link tables in the database.
  • Categories have an editable part (however, there is anyway a talk page)
  • A category can have multiple supercategories

Advantage of a pseudo-category system using backlinks:

  • Backlinks can show a tree structure: not only pages and subcategories, but also the contents of the subcategories (for each a list of pages and a list of sub-subcategories) and the contents of the sub-subcategories (for each a list of pages and a list of sub-sub-subcategories), but not the contents of the sub-sub-subcategories, up to three levels are shown; see Cat:Help and Cat:Municipalities of the Netherlands.

Alternatively a template (either a dummy one, specially for this purpose, or one with contents) can function as a supercategory, used in connection with backlinks. In that case:

  • also multiple supercategories are possible
  • combined content of subcategories is shown in one list, not grouped by subcategory (the tree structure is not shown, but it can be used by taking the backlinks at a lower node, showing the smaller set)
  • the restriction of three levels (in the case of using redirects) does not apply; for example page Aijkl in the category Aijk in the category Aij in the category Ai in the category A (represented by Aijkl calling template Aijk, etc.) can be shown in the list of pages in category A (the backlinks of template A).

"What links here" tends to be a by-product of links that are useful anyway (although links may be put with this use in mind), while category links are put specially to produce a category page.

Putting a category tag on a test page, user page, etc. (also if done indirectly by including a template with a category tag) is considered to pollute the category, while regular links from such pages showing up in "what links here" is considered harmless.

Therefore:

  • when copying text to such pages, category tags have to be removed; alternatively, convert the category to a link by adding a leading colon after the brackets. For example, "[[:Category:Art]]" is a link to the category, not an assignment to a category.
  • when including a template that is in a category, do not use the template feature, but use "subst" or copy-and-paste, and delete the category tags.

Applying "What links here" and "Related Changes" to a category

For the "What links here" feature, only the links in the editable part of the page count, not the links to the pages in the category.

For a category, the "Related Changes" feature gives the changes in the pages in the category (according to the current category page, so excluding the pages that have potentially been added and including those that have potentially been removed, through addition or deletion of a template to/from the category, as explained above)

  • for subcategories: the changes in their editable parts only
  • for images (image pages): the changes in their editable parts only.

It does not show the changes in pages linked from the editable parts of the category. Possible workarounds:

  • The editable part can be put in a template. The category tags (which have no effect on Related Changes anyway) can better be kept out of the template, because on the pages of these supercategories the template would be listed under the articles in those categories. Whether interwiki links (with or without interlanguage link feature) are in the template or not does not make a difference, provided that the template is not used elsewhere.
  • Related Changes is applied to a page that calls the category as a template: {{:Category:Category name}}; only the editable part is included in the page; the page could be specially created for this purpose and call multiple categories. However, this page will then be listed in the supercategory pages of each category.

As usual (but as opposed to a watchlist) the changes in the corresponding talk pages are not shown.

Detection of additions to a category

With "Related Changes" one can find pages which are newly in a category due to addition of a category tag or the tag of a template that is in the category. Addition of pages through addition to the category of a template is seen indirectly: one can see the change in the template, and then check which pages call the template. This even shows pages which are only potentially in the category (see above).

Detection of deletions from a category

Unfortunately there is no similar way to detect a deletion from a category.

Conventions and project-specific settings

Each page is typically in at least one category. It may be in more, but it may be wise not to put a page in a category and also in a more general category.

Each category, except one top-level category, is typically in at least one higher level category.

Check the conventions in a project and make yourself familiar with the categories in use before assigning pages and subcategories to categories and before creating new categories.

For category names the usual rules for case-sensitivity of page names apply: they are case-sensitive beyond the first character, but in most projects the first character is case-insensitive. So be aware that you create a new category if the capitalization beyond the first character is not the same.

How categories are implemented

(partly repeating the above)

Each of the pages in the Category namespace represents a so-called category, a kind of grouping of related pages. For example, this page belongs to "Category:English documentation". When a page belongs to one or more categories, this information appears at the bottom of the page (or in the upper-right corner, depending on the skin being used).

The page of the category contains text that can be edited, like any other page, but when displaying the page, the last part of what is displayed is an automatically generated, alphabetical list of all pages in that category, in the form of links (in fact ASCII order, see Help:Special page).

For a complete list of categories, see Special:Categories. Individual wikis may have their own top-level categories, such as w:Category:Categories in Wikipedia. For categories in Meta-Wiki, see m:Meta:Categories.

New categories can be created and edited in the same way as any other regular page¹, but when displayed, an automatically generated, alphabetical list of all pages in that category appears at the bottom.

You can assign a category to a page simply by adding "[[Category:categoryname]]" to the page's wikitext source. Substitute the actual name of the category in place of categoryname.

To be specific, in order to add an article called "Albert Einstein" to the category "People", you would edit the article and add "[[Category:People]]" (no quotes) into its page source somewhere. Exactly where doesn't matter, but the Wikipedia policy, for example, is to put it after the article text, but before any interlanguage links.

Category page note

You can include the template template:category note {{category note}} into the category page's description, which can link to your top level category and include basic help.

here it is for this site

Translate
This page is a category.


Large categories

If a category is large, there are multiple pages. A page with e.g. the name range Leiden-Rotterdam shows the subcategories, articles and images in that range, together up to 200. Somewhat confusingly, the subcategory count and article count apply to that name range. The editable part of the page is repeated on each of the set of pages.

To start the list at a given name, use a URL like http://en.wikipedia.org/w/index.php?title=Category:American_actors&from=Ford

A category TOC with such links can be useful. If foreign or otherwise special characters occur, it seems best to order the TOC in accordance with their position in the full list. For example É could be positioned:

  • at E (sortkey of Échange is Echange)
  • between E and F (sortkey of Échange could be E~change or "F change" with two spaces)
  • after Z (system order, i.e. the order if no sortkeys are used)

If É in the TOC is between E and F but no sort keys are used, it is confusing that when following the link Z, at the end there are pages starting with É.

Examples of large categories:

See also:

  • collating
  • category sorting
  • list of category TOCs in various Wikipedias
  • Template:A-Z containing "[[#A|A]] [[#B|B]] [[#C|C]] [[#D|D]] [[#E|E]] [[#F|F]] [[#G|G]] [[#H|H]] [[#I|I]] [[#J|J]] [[#K|K]] [[#L|L]] [[#M|M]] [[#N|N]] [[#O|O]] [[#P|P]] [[#Q|Q]] [[#R|R]] [[#S|S]] [[#T|T]] [[#U|U]] [[#V|V]] [[#W|W]] [[#X|X]] [[#Y|Y]] [[#Z|Z]]<noinclude>[[Category:Navigational templates]]</noinclude>" (see the Talk page for other versions)

Multiple tags for adding a page to a category

Multiple tags for adding a page to a category do not cause multiple listing in the category page, not even if different sortkeys have been specified: only the last tag is effective (also, if that has no sortkey, this overrides a sortkey specified in a previous tag). See Help:Demo 1.


Usage

"Is a member of" can be any binary relation over the set of all pages and the set of categories, When we consider the subcategory relation, we consider the restriction (subset) of the binary relation, to one over the set of categories only. It is a directed graph.

Usually categories are applied in such a way that page A (hence, in particular, category A) is directly or indirectly a member of category B if and only if the set of information about A is a subset of the set of information about B. This would imply that categories form a directed acyclic graph.

Nevertheless, occasionally a category cycle may occur such as:

Humans->Apes->Primates->Mammals->Animals->Tree of life-> Biology->Science->Human societies->Humans

In this case the cycle is due to a shift from the object of study, through the activity of studying, to the beings doing the study: the seemingly wrong arrangement with the info about animals supposedly being a subset of the info about humans represents the fact that humans study animals.

See also w:en:Wikipedia:Categorization and its talk page.

Moving a category page

The only way to move a category page is to manually change all category tags that link to the category, and copy the editable part. There is no automatic way to move a category page in the way one moves an article page.

Lists versus categories

For a comparison see:

See also

Links to other help pages

Help contents
Meta · Wikinews · Wikipedia · Wikiquote · Wiktionary · Commons: · Wikidata · MediaWiki · Wikibooks · Wikisource · MediaWiki: Manual · Google
Versions of this help page (for other languages see further)
What links here on Meta or from Meta · Wikipedia · MediaWiki
Reading
Go · Search · Namespace · Page name · Section · Backlinks · Redirect · Category · Image page · Special pages · Printable version
Tracking changes
Recent changes (enhanced) | Related changes · Watching pages · Diff · Page history · Edit summary · User contributions · Minor edit · Patrolled edit
Logging in and preferences
Logging in · Preferences
Editing
Starting a new page · Advanced editing · Editing FAQ · Export · Import · Shortcuts · Edit conflict · Page size
Referencing
Links · URL · Interwiki linking · Footnotes
Style and formatting
Wikitext examples · CSS · Reference card · HTML in wikitext · Formula · Lists · Table · Sorting · Colors · Images and file uploads
Fixing mistakes
Show preview · Reverting edits
Advanced functioning
Expansion · Template · Advanced templates · Parser function · Parameter default · Magic words · System message · Substitution · Array · Calculation · Transclusion
Others
Special characters · Renaming (moving) a page · Preparing a page for translation · Talk page · Signatures · Sandbox · Legal issues for editors
Other languages:
English · Deutsch · español · français · italiano · Nederlands · português · português do Brasil · Türkçe · русский · 日本語 · 中文 · עברית
  1. ↑ Omid Nezami
Retrieved from "https://meta.wikimedia.org/w/index.php?title=Help:Category&oldid=334431"