Wikipedia:Tip of the day/August 6, 2008
Wikipedia has an index system called Categories, in which links to articles are provided based on category tags included in each article.
To add an article to a particular category, add [[Category:Category name]] to the article's text (preferably at the bottom). The assigned category should now show up at the bottom of the article, and a link to the page should show up on the indicated category page in Wikipedia's category system.