:Every article in WP is part of a hierarchy. As an example consider the article series  History - History of the world - History of the United States - History of New York. Obviously History of New York does not belong in Category:History since it is the wrong level in the hierarchy. Articles should generally be placed in the lowest level possible and only the most relevant categories should be added to an article. Overuse of categories clutters up the article page as well as the category page. And since categories are used as a navigational aid this clutter makes them less useful. Another reason why I removed the ten categories was that some of them were only of a minuscule relevance. Categories are black and white. Articles are in it or they are not. Therefore, only categories that have a high degree of relevance to the article should be added. The articles themselves are used to link wide ranging topics. Categories on the other hand collect closely related topics.    -