fo page sizes

wrt top margins I see

page.margin.top
body.margin.top
region.before.extent.

I'm looking for specific sizes,
A smaller page within A4,
   so I want a top/bottom page margin of 43.5mm,
then the regions within this.

I.e. region-before offset by 43.5mm below the top of the page.
page.margin.top seems not to be this setting?

What should it be please?

TIA


regards

-- 
Dave Pawson
XSLT XSL-FO FAQ.
http://www.dpawson.co.uk