Categorization

ISOGG Wiki namespaces
Basic namespaces		Talk namespaces
0	Main	Talk	1
2	User	User talk	3
4	ISOGG Wiki	ISOGG Wiki talk	5
6	File	File talk	7
8	MediaWiki	MediaWiki talk	9
10	Template	Template talk	11
12	Help	Help talk	13
14	Category	Category talk	15
16	Portal	Portal talk	17
100	Event	Event talk	101
102	Timeline	Timeline talk	103
104	YTree	YTree talk	105
106	Famous DNA	Famous DNA talk	107
Virtual namespaces
-1	Special
-2	Media

This page contains guidance on the proper use of the categorization function. For information on the mechanics of the function, category syntax, etc., see Help:Category. For the category system itself and the list of all categories found on the ISOGG Wiki, see Category:All Categories.

Overview

The central goal of the category system is to provide navigational links to all ISOGG Wiki pages in a hierarchy of categories which readers, knowing essential—defining—characteristics of a topic, can browse and quickly find sets of pages on topics that are defined by those characteristics.

Categories are not the only means of enabling users to browse sets of related pages. Other tools which may be used instead of or alongside categories in particular instances include lists and navigation boxes.

Creating category pages

To create a category, first add an article to the category. Do this by editing the article page. Move the edit cursor to the foot of the article page, and add the category of the article: e.g. [[Category:The category name here]], and save your edit. The category name will appear as a red link in the category list at the bottom of the article page.

To create the relationship to a parent category click on the red link. Add an appropriate parent category name to the foot of the new category page (by repeating the instructions in the paragraph above, but substituting the word "category" and "parent category" for "article" and "category", respectively, in the paragraph above).

Sometimes, a common-sense guess based on the title 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), 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.

• All new category pages should include the template {{catheader}} which adds additional information on the category and a link to use 'Category tree' for category browsing.
• A maximum of 200 category entries are displayed per screen.
• Subcategories are split alphabetically along with the articles, which means that the initial screen of a split category may not include all its subcategories.

Categorizing pages

Every ISOGG Wiki page should belong to at least one category. (However, there is no need to categorize talk pages, redirects, or user pages, though these may be placed in categories where appropriate.)

In addition, each categorized page should be placed in all of the most specific categories to which it logically belongs.

While it should typically be clear from the name of an existing category which pages it should contain, some additional text on the category page may sometimes provide additional information on potential category contents.

One 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: If you're not sure where to categorise a particular page, add the {{uncategorized}} template to it—other editors will help find appropriate categories for it.

Articles

Particular considerations for categorizing articles:

• By convention, category declarations are placed at the end of the wikitext.
• The order in which categories are placed on a page is not governed by any single rule (for example, it does not need to be alphabetical, although partially alphabetical ordering can sometimes be helpful). Normally the most essential, significant categories appear first.
• An article should never be left with a non-existent (redlinked) category on it. Either the category should be created, or else the link should be removed or changed to a category that does exist.

Files/images

Files and images uploaded to the ISOGG Wiki should have a proper category, which is a sub-category of the Category:Image.

User pages

It is not necessary to categorize user pages, nor their associated talk pages. If you wish, you can add your user page to the Category:User pages, a catch-all category to aid in finding a user.

Categorization using templates

Many templates may 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.

Redirected categories

Do not create inter-category redirects, simply stated, redirection from one category to another category. The ability to move a category to another category and leave behind a redirect is not an available function. For technical reasons, the preferred method is to create the new category and re-categorize the pages desired assigned to it.

Sort keys

Sort keys are sometimes needed to produce a correct ordering of member pages and subcategories on the category page. For the mechanics, see Sort order on the help page.

Because the software uses an imperfect computer sorting rather than true alphabetical ordering (see details), it is important that some sort keys be adjusted consistently. Until recently, the biggest needed adjustment was to consistently capitalize the first letter of each word and make lower case all other letters.

Category tree organization

Categories are organized as overlapping, formed by creating links between inter-related categories. 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. There is one top-level category, Category:All Categories. 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.

Subcategorization

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.

Many subcategories have two or more parent categories. 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.