The term "WikiProject" is reserved for projects created for the purpose of managing a specific family of information within Wikipedia. It is not a place to write encyclopedia articles (that's done on the article pages themselves), but a resource to help coordinate and organize article writing. The attached talk pages are a convenient forum for those interested in a particular project. WikiProjects can also have associated Portals. The Tip of the day project is not a WikiProject, because it coordinates the development of self-referential content (Wikipedia instructions) rather than content of the encyclopedia itself (such as Roman Empire). Note that some self-referential projects have broken this guideline.
Read more: Wikipedia:WikiProject