This is what is says in Adobe Help:
Sort Ascending or Descending
You can sort the requests listed in the Request Manager in ascending or descending order.
Click on the columns names in the table header. The column shows the sort order by displaying a triangle icon in the table header. If the triangle is pointing down, sort order is descending (for alphanumeric data, 9-1 and Z-A), while if pointing up, the sort order is ascending (for alphanumeric data, 1-9 and A-Z). The default sort order is ascending.
This feature does not work. It is essential to have.