Changing the <h> levels

The DocBook stylesheets generate HTML heading elements H1, H2, H3, etc. according to the hierarchy of elements in the document. However, you may want to alter which HTML heading level gets assigned to a particular element. Keep in mind that you need not customize the XSL just to change the styling, because an external CSS stylesheet can handle that. But if you need to change the heading level elements, the following are some guidelines.