Help talk:Categories

Sub-categorising
Should anyone add information here on how to put one category under another (subcategory)?
 * This was done a while back (but since the question was asked) --HappyDog 16:35, 27 August 2007 (UTC)

Hiding categories
How does one hide category display?


 * You can hide the category links at the bottom of a page using CSS (e.g. ).  --HappyDog 01:36, 28 June 2007 (UTC)

But how does one hide an article (or something like a template) from being included within a category?

Intro
I think it's important to define what a Category is. It could be placed before the help section where it explains how to add a category, as a noob might not know what the Category does. Just a suggestion. --Hawkwynd 12:23, 24 August 2007 (UTC)


 * Thanks. It's a wiki, so feel free to add this kind of text yourself!  In the meantime, I've added a rough-and-ready intro.  Please tweak it if you feel the need. --HappyDog 16:35, 27 August 2007 (UTC)

second independent category system
I want to introduce a second category system in my wiki or let me call it an "advanced Tag-System". The idea is to tag every page with some words as links - similiar to the categorie syntax. When I then click this words, I want to see a page with the content of "what links here". Besides this I want to keep the standard category tree. Have anyone has an idea, how to realize this? --87.162.127.221 13:43, 14 October 2007 (UTC)
 * Try Semantic MediaWiki? --141.14.26.125 08:21, 19 February 2008 (UTC)

Language
Could someone please add a guide on how one can change the name "Category" into something localised in other languages? --David Munch 14:41, 12 April 2008 (UTC)
 * I would think that would be the "MediaWiki:Categories" page of your wiki; accessible via "Special:Allmessages". --Lance May 12:49, 12 June 2008 (UTC)

Sorting question...
In an interesting display, I have managed to thoroughly confuse myself with categories. When sorting using the "" suggestion, I've gotten my templates to exhibit the appropriate behavior. The category is "Templates", and the namespace is the default "Template". This works perfectly. However, when I tried this with another category (originally the same name in category as in namespace), they simply sort by the namespace. I've since renamed the category and left the namespace the same. It still sorts by the namespace. The only difference in the two situations that I can see now is that the problematic pages are also tied to another category. Do categories not sort if the pages are attached to more than one? --Lance May 18:04, 11 June 2008 (UTC)
 * Okay, so just in case there are others out there who may have a similar issue. Any level of pride does not prohibit me from saying that the issue above was not only my fault, it was my complete ignorance of the product's features. Essentially, I had expected that namespaces would be created just as any other page; through usage. Granted, this would not be feasible in situations like Wikipedia, so I can see why it is not that way. So that is what the delta was between the two situations; one was a real namespace and had a, the other was not and did not. However, in the interest of possibly lending a hand to anyone else running across this issue, please see Manual:$wgExtraNamespaces before just creating "Something:Like_this", as it will not become a namespace without setting it up ahead of time.

in pages categorized via templates
I'm facing a problem to which I haven't yet found any answer or solution: in a wiki I collaborate to, we have a kind of pages that are categorized in two different ways: When I decided for DEFAULTSORT in place of the old procedure of manually inserting a sort key in each category tag (and for the templates, by passing the sort key as parameter), I discovered that DEFAULTSORT only works for the categories local to the page, but not for the ones inserted by the templates. Is there a way to change this behavior and force all categories to follow DEFAULTSORT? Even a tweak in the wiki code would be welcome! Thanks --Capmo 21:49, 12 October 2008 (UTC)
 * 1) via directly receiving category tags (say,  ), and
 * 2) by receiving templates that categorize the page indirectly (i.e.: templates   that insert the page in categories  ).


 * should apply also to categories included via templates. However, keep in mind that it's the default sort key: any explicitly specified sort key will override it.  —Ilmari Karonen 22:58, 14 December 2008 (UTC)


 * Thanks for your reply, you were right: some of the templates had a sortkey code defined in them that was preventing DEFAULTSORT from working properly. It was something like this:  . When no sortkey was passed as parameter, the "magic word" PAGENAME would become active and override DEFAULTSORT. When I removed all that and left only    everything worked fine! Capmo 04:50, 15 December 2008 (UTC)

Changing items listed per category
I know I can place the following global variable into LocalSettings.php

$wgCategoryPagingLimit = 600;

To alter all categories in a Wiki.

But someone said that the latest MediaWiki now allows this to be done on a per category basis?

If so, does anyone know the magic word I add into a category page to do this?

I can't find it listed.

--Stuart Halliday 12:10, 20 January 2009 (UTC)

Sort by more than one character
What if I want to sort by year? If I do it will be listed on the :Category:Year page under "2", right along with articles in I would rather have it be listed under "2009," so that "2008" shows up separately.

And what if I want a subcategory to be listed in a parent category by a different name? For example, I have Category 2009 as a subcategory of Articles, and instead of 2009 showing up on the Category:Articles page under subcategory header 2 I want it to be listed under subcategory header Year.

And what if I want to list the same article in the same category with multiple keys? If I do: It will only appear once on the :Category:Author page, under "A". I would like the Author page in this case to list a header "Aleph" and all pages with him listed as an author, and a separate header "Gammow" with the same.


 * I know it doesn't work to put the same category twice, even with different sort keys. In fact, there's a cleanup project that's identifying articles like that, so that it can be corrected.
 * One thing you can do (and I don't know if this fits what you had in mind) is put categories on redirect pages. Two examples are the English Wikipedia pages for Nickolas Ashford and Valerie Simpson, which both redirect to Ashford & Simpson. The redirect pages for their individual names have default sort keys for their individual names, and include categories that apply to them as individuals. One category listed on both pages is "Living people", so they'd appear separately in that category. Does that help? --Auntof6 23:14, 5 June 2009 (UTC)