My users ask for this in almost every application.  When a grid is grouped, the users want to see the groups in an order that indicates some ranking by an aggregate value. For example, If SALES-DETAIL table is grouped by SALESPERSON, the default alphabetic order of the groups might be AMELIA, BARBARA, CARLOS, DAVID, HARRY, THOMAS, ZELDA. But users want to see the groupings in descending order by the salesperson's TotalSales, which might be HARRY, ZELDA, AMELIA, THOMAS...etc. So we need a way to specify a custom-group-sortorder. And to be perfectly clear, that is the sequence of groups with respect to each other, not the order of detail data inside the group. The detail records might be sorted chronologically by SalesDate regardless of the order of the group relative to each other. In SQL the equivalent would be  ... GROUP BY SALESPERSON ORDER BY SUM(TotalSales) DESC(ending). This feature would work hand-in-glove with another requested feature, showing the group footer when the group is collapsed.