&lt;!DOCTYPE para PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN"
          "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"&gt;
&lt;para&gt;
The symbolic constants for error numbers are defined in
&lt;filename class='headerfile'&gt;errno.h&lt;/filename&gt; in
&lt;filename class='directory'&gt;/usr/include/sys&lt;/filename&gt;.
&lt;/para&gt;