A puzzle for any DocBook gurus that may be lurking around:

I'm using DocBook XML (with an XSL stylesheet) for documenting a moderately large software project, containing several specialized components (tovid, link in my sig).

I want the DocBook structure to be a "book" containing several "chapter"s. I'm putting all of the documentation in a single .xml file, for now.

I use xmlto to generate HTML output:

I have this definition in my XSL:

My HTML output looks good, but for some reason H2-level headings are being used for chapter titles. H2-level headings are also being used for sub-chapter section titles.

This is a known issue. Googling found suggestions like this to style the H2s with CSS. These suggestions imply "it looks the way you want without actually being correct" - they also note that you can customize the XSL to make it correct, but why bother.

Also a post from Norman Walsh himself, from almost four years ago, that he thought it was a problem and should be fixed somehow. But again, no hint how to accomplish it. Further Googling has been essentially fruitless, except for a few groans that HTML heading levels aren't deep enough to fully support DocBook anyway. (Really, if you need more than 6-deep headings in a single HTML file, you should think about reorganizing).

It all boils down to this: Can anyone tell me how I can get my XSL stylesheet to cause correct heading generation? I want chapter titles to generate H1s, instead of H2s that I have to kludge with CSS for correct appearance.

Thanks in advance!