URLs and file names can be quite long, and that can lead to problems when using full justification (so that the left and right hand sides of a paragraph line up). There are certain places in a URL or file name where it is safe to break over two lines, and there is a TeX package that knows how to break URLs and file names properly.
In the stylesheet customization layer (see the Section called selfdocbook.dsl in Appendix A) the ulink and
filename elements are redefined to output
formatting instructions like \url{…} and
\path{…}.
By default, URLs and file names marked up in this way are rendered magenta. To turn this off, put \hypersetup{colorlinks=false} in your jadetex.cfg (see the Section called jadetex.cfg in Appendix A).
The ulink element shown in the Section called selfdocbook.dsl in Appendix A handles the case where there are no
child elements—such as with <ulink
url="http://…"></ulink>—as
well as the case where the ulink text is the
same as the link itself, such as with <ulink
url="http://…">http://…</ulink>.