If an article is tagged as in need of cleanup, it means the article needs to be improved for something, as it has a fault. For example, if an article is not written in the correct style, if it is written from a non-encyclopedic point of view (eg. first person), if it has lots of grammar or spelling errors, or generally needs "cleanup".

To tag an article for cleanup, add the template {{cleanup}} to the page. This will also categorize the tagged article in Category:Articles in need of cleanup, where a complete list of articles needing cleanup can be seen (check out Category:Articles in need of attention for even more).