An item is any of the following:
</p>
<ul>
<li>A single character, matching that character.</li>
<li>Two characters separated by <tt>-</tt>.  This is shorthand for the
full range of characters  between those two (inclusive) in the
collating sequence.  For example, <tt>[0-9]</tt> in ASCII matches any
decimal digit.</li>
<li>A collating element enclosed in <tt>[.</tt> and <tt>.]</tt>,
matching the collating element.  This can be used to include a literal
<tt>-</tt> or a multi-character collating element in th