XSLT/XSL-FO: How to get a special layout for the first

Hi all,

I'm trying to create a PDF from an XML document containing a book
manuscript, using XSLT/XSL-FO.

In my XML document, a new chapters is identified by a <CHAPTER> tag.

I want the first page of every chapter to look different from the rest
of the chapter pages (on the first page I want a bigger region-before
size and the chapter name in region-before, but no chapter name on the
rest of the pages).

As far I understand, the solution may have something to do with
fo:page-sequence-master, it seems to be able to assign a special
page-master to the first page. I understand that I can identify the
first page of the document this way, but how do I identify the first
pages of the rest of the chapters? Don't I somehow have to make it
react whenever a <CHAPTER> tag comes up, by invoking my "page-master
for first pages"? How do I make it react on <CHAPTER> tags?

Kind regards,
Martin