diff --git a/Modules/Core/resource/Interactions/DisplayConfigPACS.xml b/Modules/Core/resource/Interactions/DisplayConfigPACS.xml
index 40dee1e9d7..6d242ef483 100644
--- a/Modules/Core/resource/Interactions/DisplayConfigPACS.xml
+++ b/Modules/Core/resource/Interactions/DisplayConfigPACS.xml
@@ -1,70 +1,82 @@
+<!--
+* - PACS : The original interaction scheme
+*   - left mouse button   : set crosshair
+*   - middle mouse button : UNUSED
+*   - right mouse button
+*	  with shift modifier : moving
+*   - right mouse button
+*	  with ctrl modifier  : zooming
+*   - right mouse button  : adjust level window
+*   - wheel               : scrolling
+-->
 <config>
   <!-- Zoom sensitivity -->
   <param name="zoomFactor" value="5"/>
-  <!-- Zoom either by moving mouse leftright or updown -->
+  <!-- Zoom either by moving mouse left-right or up-down -->
   <param name="zoomDirection" value="updown"/>
-  <!-- scrolling either by moving mouse leftright or updown -->
+  <!-- scrolling either by moving mouse left-right or up-down -->
   <param name="scrollDirection" value="updown"/>
   <!-- Sets how many pixel the mouse has to be moved for scrolling 1 slice-->
   <param name="pixelPerSlice" value="3"/>
   <!-- when scrolling restart at beginning of volume, when end is reached-->
   <param name="autoRepeat" value="true"/>
   <!-- react to an event, even tough is was already processed by a DataInteractor-->
   <param name="alwaysReact" value="true"/>
-  <!-- Crosshair -->
+
+  <!-- Left mouse: Crosshair -->
   <event_variant class="MousePressEvent" name="SetCrosshair">
     <attribute name="EventButton" value="LeftMouseButton"/>
   </event_variant>
   <event_variant class="MouseMoveEvent" name="MoveCrosshair">
     <attribute name="ButtonState" value="LeftMouseButton"/>
   </event_variant>
   <event_variant class="MouseReleaseEvent" name="EndMoveCrosshair">
     <attribute name="EventButton" value="LeftMouseButton"/>
   </event_variant>
-  <!-- Moving -->
+
+  <!-- Right mouse with shift modifier: Moving -->
    <event_variant class="MousePressEvent" name="StartMove">
     <attribute name="EventButton" value="RightMouseButton"/>
     <attribute name="Modifiers" value="shift"/>
   </event_variant>
   <event_variant class="MouseReleaseEvent" name="EndMoving">
     <attribute name="EventButton" value="RightMouseButton"/>
     <attribute name="Modifiers" value="shift"/>
   </event_variant>
   <event_variant class="MouseMoveEvent" name="Moving">
     <attribute name="ButtonState" value="RightMouseButton"/>
     <attribute name="Modifiers" value="shift"/>
   </event_variant>
-  <!-- Zooming -->
+
+  <!-- Right mouse with ctrl modifier: Zooming -->
   <event_variant class="MousePressEvent" name="StartZoom">
     <attribute name="EventButton" value="RightMouseButton"/>
     <attribute name="Modifiers" value="ctrl"/>
   </event_variant>
    <event_variant class="MouseMoveEvent" name="Zooming">
     <attribute name="ButtonState" value="RightMouseButton"/>
     <attribute name="Modifiers" value="ctrl"/>
   </event_variant>
   <event_variant class="MouseReleaseEvent" name="EndZooming">
     <attribute name="EventButton" value="RightMouseButton"/>
     <attribute name="Modifiers" value="ctrl"/>
   </event_variant>
-  <!-- scrolling -->
-  <event_variant class="MousePressEvent" name="StartScroll">
-    <attribute name="EventButton" value="MiddleMouseButton"/>
-  </event_variant>
-  <event_variant class="MouseReleaseEvent" name="EndScrolling">
-    <attribute name="EventButton" value="MiddleMouseButton"/>
-  </event_variant>
-  <event_variant class="MouseMoveEvent" name="Scrolling">
-    <attribute name="ButtonState" value="MiddleMouseButton"/>
-  </event_variant>
-   <!-- LevelWindow -->
+
+  <!-- Right mouse: LevelWindow adjusting-->
   <event_variant class="MousePressEvent" name="StartAdjustLevelWindow">
     <attribute name="EventButton" value="RightMouseButton"/>
   </event_variant>
   <event_variant class="MouseReleaseEvent" name="EndLevelWindow">
     <attribute name="EventButton" value="RightMouseButton"/>
   </event_variant>
   <event_variant class="MouseMoveEvent" name="adjustlevelwindow">
     <attribute name="ButtonState" value="RightMouseButton"/>
+
+  <!-- Mouse wheel: Scrolling through planes -->
+  <event_variant class="MouseWheelEvent" name="PlaneUP">
+    <attribute name="ScrollDirection" value="up"/>
+  </event_variant>
+  <event_variant class="MouseWheelEvent" name="PlaneDown">
+    <attribute name="ScrollDirection" value="down"/>
   </event_variant>
 </config>