/li>
<li><tt>upper</tt> - upper case letters</li>
<li><tt>xdigit</tt> - hexadecimal digits</li>
</ul>
</ul>
<p>
To include a literal <tt>-</tt> in the list, make it either the first
or last item, the second endpoint of a range, or enclose it in
<tt>[.</tt> and <tt>.]</tt> to make it a collating element.  To
include a literal <tt>]</tt> in the list, make it either the first
item, the second endpoint of a range, or enclose it in <tt>[.</tt> and
<tt>.]</tt>.  To use a literal <tt>-</tt> as the first
endpoint o