In order for the parameters in this section to make sense, it is useful to consider Figure 1, “”.
First, let's consider the regions on the page.
The white region is the physical page. Its dimensions are determined by the page.height and page.width parameters.
The yellow region is the region-body. The size and placement of the region body is constrained by the dimensions labelled in the figure.
The pink region at the top of the page is the region-before. The darker area inside the region-before is the header text. In XSL, the default display alignment for a region is before, but the DocBook stylesheets still explicitly make it before. That's why the darker area is at the top.
The pink region at the bottom of the page is the region-after. The darker area is the footer text. In XSL, the default display alignment for a region is before, but the DocBook stylesheets explicitly make it after. That's why the darker area is at the bottom.
The dimensions in the figure are:
The page-master margin-top.
The region-before extent.
The region-body margin-top.
The region-after extent.
The page-master margin-bottom.
The region-body margin-bottom.
The sum of the page-master margin-left and the region-body margin-left. In DocBook, the region-body margin-left is zero by default, so this is simply the page-master region-left.
The sum of the page-master margin-right and the region-body margin-right. In DocBook, the region-body margin-right is zero by default, so this is simply the page-master region-left.
Table of Contents