&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;
On most UNIX systems, functions signal a &lt;errorname&gt;File
Not Found&lt;/errorname&gt; error by returning
&lt;errorcode&gt;ENOENT&lt;/errorcode&gt;, defined in 
&lt;filename&gt;errno.h&lt;/filename&gt;.  This is usually a
&lt;errortype&gt;recoverable&lt;/errortype&gt; (non-fatal) error.
&lt;/para&gt;