The overview file is used in conjunction with the javadoc tool. It is a HTML file, which is converted to DocBook and inserted before the reference section.

If the overview file contains a h1 tag as the first tag after the body tag, the doclet assumes every h1 tag to be a new chapter and creates the document structure upon the information found in the file. So it is possible for an author to structure the content of the document before the reference section on his own. You can create as many chapters, sections and subsections as you want before the generated reference part.

If the first tag after the body tag is not a h1 tag, the doclet creates a chapter "Overview". Any header tags will appear as subsections of this chapter.