PGVWiki:Categorisation

For detailed technical information on how to use categories, see Wikipedia's Help:Category.

Approaches to Category Navigation

Categories are utilised in two ways by users of the PGVWiki site in order to find articles of interest and relavence. These approaches have to be considered when formulating and expanding the hierarchy of categories.

Top-Down Approach

A user can browse the top-level of the categories hierarchy via the Category:Contents page. The user then drills-down towards categories of increasing specificity by clicking the links within the subcategory section of the category page. This way the user can navigate towards articles of relavence.

Bottom-Up Approach

A user may have already found an article of relavence and wishes to find similar or a broader range of articles. The user can click on a category link at the bottom of the page to find articles within the same category. Following a similar link at the bottom of a category page will allow you to view the parent category in order to located more broadly categorised articles.

How to categorise an article

Categorising an article is simply performed by editing it, and including one or more category declarations. For instance, to add the Blocks article to the "PhpGedView" category, you would edit the article and enter [[Category:PhpGedView]] at the bottom, but before any interlanguage links. The appeal of categories is that they update themselves automatically, and you don't have to edit the category to add an article to it.

When adding an article to a category, or creating categories, one should be careful to use the correct categories and subcategories. Horizontal categorisation (below), refers to placing an article in the correct category while vertical categorisation refers to placing an article in the correct subcategory.

When assigning an article into categories, try to be thorough in a "horizontal" sense. You might need to poke around the category hierarchy a bit to find the right place. Try searching for articles similar to the article you are categorising to get ideas or to find the most appropriate place.

In the "vertical" dimension, placing articles only in the most specific categories they reasonably fit in. Thus, if an article relates to a Chart type in PhpGedView then it could be categorised under Category:Charts but not Category:PhpGedView since Category:Charts is a subcategory of Category:PhpGedView. It is expected that the user should be able navigate the categorise hierarchy to find related articles using one of the above approaches.

When creating categories . . .

Look before you leap

Before creating a category, look to see if one already exists. The best way to do this is to first add the category to your article but preview before saving. When previewing a page, scroll right to the very bottom of the browser window to see the categories. If the category appears in blue, the category already exists. If it is in red, then you will be creating a new category. Check the capitalisation of the category name. For any red categories, you should look for categories with similar names before creating a new category. One way to do this is to think of the parent category for the new category. Search for it and then look at the subcategories in the parent. You may find that a category already exists that is similar to the one you are thinking about creating.

Before creating a new category, familiarise yourself with all the guidelines on this page, and related pages. Categories are deleted, merged and renamed at the PGVWiki Admin's discretion, particularly if over-categorisation occurs.

Note that, although "uncreated" categories will correctly list articles that have been assigned to them, the category page itself does not exist until it is manually created. The easiest way to create the category page is to follow the red category link from your article and create a new category page with a parent category and a category description as explained in the next section.

How to create subcategories

Subcategories may be created by putting [[Category:parent_category_name]] onto the page that you would like to make into a subcategory. This may seem counterintuitive, because you edit the subcategory page rather than the parent category page.

Let's say that you wanted to make the category called Roses into a subcategory of the category called Flowers.

Step 1 - Go to the page called [[Category:Roses]], and click edit this page.

Step 2 - Place the text [[Category:Flowers]] within the body of the [[Category:Roses]] article, and save.

Finished! Roses is now a subcategory of Flowers, and [[Category:Roses]] will be visible on [[Category:Flowers]].

Links to categories

You can create a link to a category page without adding the page to that category by using a colon before the word Category. Example: [[:Category:Charts]] appears as Category:Charts.

Category sorting

Pipe tricks and sort keys

Contrary to some expectations, text after a pipe ("|") in a category link is not used in place of the category text. Rather, this text is used as the sort key on the category page itself. However, again contrary to expectations, that sort text is not displayed. For example, [[Category:User|Nathan Watson-Haigh]] used in the user page of Nathan Watson-Haigh will make the "User:Nathan Watson-Haigh" page list under N rather than U in the category.

Setting a default sort key

The default sort key of a page for categories can be changed using the {{DEFAULTSORT}} magic word. For instance, on User:Nathan Watson-Haigh, {{DEFAULTSORT:Nathan Watson-Haigh}} would cause [[Category:User]] to be equivalent to [[Category:User|Nathan Watson-Haigh]], not [[Category:User|User:Nathan Watson-Haigh]]. This is especially useful when the article belongs in many categories. If more than one default sort key magic word is present on a page, the last occurrence is the one used. The {{DEFAULTSORT}} magic word affects all categories that the article is in, regardless of the position of the magic word relative to the category. It does not just affect subsequent categories. The default sort key can be overridden for individual categories applied to an article by manually applying a sort key.

An easy way of overriding the magic word and using the current article name as the sort key is to use the {{PAGENAME}} template after the pipe, e.g. [[CATEGORY:User|{{PAGENAME}}]]. Using this template will cause the article to appear in the position appropriate to its full article name if the article is moved.