DOCBOOK: Numbering titles of sections

[Francesc Guasch <frankie at oasyssoft dot com>]

I need to number the titles of the sections of a book.
I searched the news and the mailing lists and I took a
look to the customization dtd section of the docbook book.

First of all I wonder if someone has done this before
and could send me an example DTD. All the information
I found required I had a high level of docbook knowledge.

Anyway I'm trying to do my own DTD unsuccessfully.

That's what I did:

<!ENTITY % DocBookDTD PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN"
    "/usr/share/sgml/docbook/xml-dtd-4.1.2/docbookx.dtd"
>

%DocBookDTD;
(define %section-autolabel% #t)

So this didn't work. I started searching the files in
/usr/share/sgml/docbook/xml-dtd-4.1.2. It seems dbhierx.mod
has something about the section but I still don't know 
how to do it.

Please, I know I'm missing something. What ?
Thank you.