# Generated navigation topics

If a topic in the table of contents does not specify an `href` attribute, or a toc element does not specify a `topic` element, Help will automatically generate a topic containing the topic's title, a heading to denote the start of the list of subtopics, and an unordered list of subtopic links (direct subtopics only).

Products may customize the appearance of these generated topics using CSS. Help will look for a `book.css` file at the root of the currently running product's plug-in, and will use this stylesheet to style the generated document. You may rely on the elements with the following classes to be present in the generated document, and use these to style it:

- `NavTitle`: The class of the heading containing the topic's title.
- `NavListTitle`: The class of the heading before the list of topic links.
- `NavList`: The class of the list containing the links to the direct subtopics.

For example, to hide the list bullets, you would use the following CSS rule:

    UL.NavList {
       list-style-type: none;
    }