Correct scale field document to be a dividing factor

contributed_definitions/NXregion.nxdl.xml

@@ -151,10 +151,12 @@
 	</field>
 	<field name="scale" type="NX_NUMBER">
 		<doc>
-			An optional field to define a multiplicative factor for scaling of blocked data.
+			An optional field to define a divisor for scaling of reduced data.
 			This can also be **O** + **R** in length so that each dimension's region can be
-			multiplied by a different scale. For example, in a downsampled sum, it can reduce
-			the maximum values to fit in the domain of the result data type.
+			divided by a different value. For example, in a downsampled sum, it can reduce
+			the maximum values to fit in the domain of the result data type. In an image that
+			is downsampled by summing 2x2 blocks, using :math:`\mathrm{scale}=4' allows the result
+			to fit in the same integer type dataset as the parent dataset.
 			If omitted then defined as an array of ones
 		</doc>
 		<dimensions rank="1">