A stub is an article that is too short, but not so short as to be useless. In general, it must be long enough to at least define the article's title, which generally means 3 to 10 short sentences. Note that even a longer article on a complicated topic may be a stub; conversely, a short article on a topic of narrow scope may not be a stub. Note that a stub is not just a short article. A stub is a short article where more information can be added.