html.append
html.append — Specifies content to append to HTML output
Synopsis
<xsl:param name="html.append"></xsl:param>
Description
Specifies content to append to the end of HTML files output by
the html/docbook.xsl
stylesheet, after the
closing <html>
tag. You probably don’t want to set any
value for this parameter; but if you do, the only value it should ever
be set to is a newline character: 

or