//spirit.sourceforge.net/
</pre>
<p>
        so, when the text is absent in a link markup, the URL is assumed. Example:
      </p>
<pre class="programlisting">see [@http://spirit.sourceforge.net/]
</pre>
<p>
        will generate:
      </p>
<p>
        see <a href="http://spirit.sourceforge.net/" target="_top">http://spirit.sourceforge.net/</a>
      </p>
<p>
        Boostbook also support a custom url schema for linking to files within the
        boost distribution:
      </p>
<pre class="programlisting"