Categories are the basis for Wiki Readers to find information on this wiki arranged in a topical manner.
Anyone can help in this process by putting links to a category on a page. Pages in that category can then be found by a search which begins with the clicking on the title of the category page. The category is a Reverse Index. For forward indices, see Road Map.
Note that a category is sometimes a forward index, and a Road Map is also a Reverse Index (though often incomplete). The difference between the two is mostly one of convention - categories have a conventional placement near the page bottom. Road Maps are typically not named on the pages they reference. Category pages may have no hand-edited list, while Road Maps always do. -- Dean Elvy
What should be the content of a category page? (Draft)
It should contain:
something like "(See Wiki Categories)" at the top
a short description which pages should be linked to this category
a reference to CategoryCategory at the bottom
It may contain:
references to any direct super-categories (parent categories, not other ancestor categories) at the bottom
a short statement why this category is needed
a short discussion whether this category really should exist
a short discussion on the contents of the category page
It should not contain:
any content which could as well be placed on a different page which is linked to this category
Many category pages contain a sentence like "click on the title for a list of pages in this category". While this instruction should in theory be Once And Only Once with Wiki Categories, in practice its presence on each category page makes the introduction of the Back Link mechanism a little easier for those new to Wiki.
Put a Road Map on its own page. Someone might want to link to it without including the referring page into the category.
Opinions existing on this wiki about Categorization
I created Help Using Categories to make it easier for newbies to know how to work with categories. It may be a competitor to this tag.
See original on c2.com