processed and the last value is the one that remains in the processor.
		The default value for this field is <code>"option '%s' was already defined"</code>.
	</dd>
	
	<dt><code><b>_optpat</b></code></dt>
	<dd>
		String that defines the pattern that command-line option must match.
		The pattern must define three captures, in the following order:
		<ol>
			<li><code>name</code>: name of the command-line option.</li>
			<li><code>assign</code>: assignment expression that indicates the value of the option was p