Used for lists in which each entry is marked with a sequentially incremented label.

<orderedlist>
 <listitem><para>
  This is a list element. It is prefixed with 1.
 </para></listitem>
 <listitem><para>
  This is another list element. It is prefixed with 2.
 </para></listitem>
</orderedlist>

See also listitem and itemizedlist.

http://docbook.org/tdg/en/html/orderedlist.html