In the category tree, it is important to use a sort key when categorizing an article. This aids in placing the articles in order when viewed from the category into which they are suggested to be placed. The above is written in the assumption that the user is using the CategorySelect feature. A few different sorting rules are applied here, but be careful -- individual categories may have special rules depending on the topic of the article. These will be listed on individual talk pages if they apply. Otherwise, the following situations are standard: