Listing categories in hierarchical order

<mt:IfArchiveTypeEnabled type="Category">
  <mt:TopLevelCategories>
    <mt:SubCatIsFirst><ul></mt:SubCatIsFirst>
    <mt:If tag="CategoryCount">
        <li><a href="<$mt:CategoryArchiveLink$>" title="<$mt:CategoryDescription$>"><$mt:CategoryLabel$></a>
    <mt:Else>
        <li><$mt:CategoryLabel$>
    </mt:If>
    <$mt:SubCatsRecurse$>
        </li>
   <mt:SubCatIsLast></ul></mt:SubCatIsLast>
  </mt:TopLevelCategories>
</mt:IfArchiveTypeEnabled>