diff --git a/include/data.h b/include/data.h
index 3a752c2e..e5a76462 100644
--- a/include/data.h
+++ b/include/data.h
@@ -572,8 +572,14 @@ struct Con {
 
     struct Con *parent;
 
+    /* The position and size for this con. These coordinates are absolute. Note
+     * that the rect of a container does not include the decoration. */
     struct Rect rect;
+    /* The position and size of the actual client window. These coordinates are
+     * relative to the container's rect. */
     struct Rect window_rect;
+    /* The position and size of the container's decoration. These coordinates
+     * are relative to the container's parent's rect. */
     struct Rect deco_rect;
     /** the geometry this window requested when getting mapped */
     struct Rect geometry;