There is another grouping technique which uses "In" to identify exact values to add to a group. An example of this is in the new "Plugging Leaks 03 - Flop Hand Strength" report.
<Grouping FieldExpression="FLOP.MadeHandValue" ColumnName="FlopMadeHandValue" ColumnHeader="Flop Made Hand Value">
<Ranges>
<Range In="20" RangeName="Overpair" />
<Range In="40,41,42,60,61,62,63,64,65,66,67,68,80,81,82, 8 3,100,101,102,103,104,120,121,122,123,124,125,140, 141,160,161" RangeName="2 Pair+" />
<Range In="23,24" RangeName="Top Pair Q+ Kicker" />
<Range In="0,10,11,21,22,25,26,27,28,29,30,31,32,43,44,4 5 ,46,47,48,49,69,84,105,106,107,108,126,142,162" RangeName="Top Pair Weak Kicker or Worse" />
<Range In="-1" RangeName="Unknown" />
</Ranges>
</Grouping>
Here I am identifying actual hand value ID's and assigning them into one of 4 groups. Again this is a case where you need to know what the ID's represent but this will all be documented.