Clarify the conventions for rotations in left and right handed coordinate system

base_classes/NXtransformations.nxdl.xml

@@ -151,16 +151,31 @@
 			<doc>
 				Three values that define the axis for this transformation.
 				The axis should be normalized to unit length, making it
-				dimensionless.  For ``rotation`` axes, the direction should be
-				chosen for a right-handed rotation with increasing angle.
+				dimensionless.
 				For ``translation`` axes the direction should be chosen for
 				increasing displacement. For general axes, an appropriate direction
 				should be chosen.
 
 				Note that if the ``NXtransformation`` depends on a coordinate system
 				(i.e., its ``depends_on`` attribute points to an instance :ref:`NXcoordinate_system`),
-				the rotation is right handed in that coordinate system, even if the the coordinate system
-				itself is left-handed (as defined by the determinant of its base vectors).
+				for ``rotation`` axes, the rotation convention is the same as the handedness
+				of the coordinate system (as defined by the determinant of its base vectors):
+
+				* Rotations in left-handed coordinate systems are left-handed (i.e., they follow the 
+				  left-hand rule). In a left-handed coordinate system, positive rotation about an
+				  axis is clockwise when looking from the origin in the direction of the 
+				  positive axis (from the origin towards infinity).
+
+				* Rotations in right-handed coordinate systems are right-handed (i.e., they follow the 
+				  right-hand rule). In a right-handed coordinate system, positive rotation about an
+				  axis is counter-clockwise when looking from the origin in the direction of the 
+				  positive axis (from the origin towards infinity).
+
+				Note that by using this convention, the transformation matrices in both left- and
+				right-handed coordinate systems are the same.
+
+				By default, ``rotation`` axes that do not explicitly depend on a coordinate system,
+				the direction should be chosen for a right-handed rotation with increasing angle.
 			</doc>
 			<dimensions rank="1">
 				<dim index="1" value="3" />