diff --git a/Physics/MovingParticles3.mch b/Physics/MovingParticles3.mch
index 7033c369c69df22901fabac98cd2b51a58a9427c..451a01c9f9c6ef2d060aeab972420da624178985 100644
--- a/Physics/MovingParticles3.mch
+++ b/Physics/MovingParticles3.mch
@@ -16,7 +16,8 @@ DEFINITIONS
                                      )  ) ) // acceleration due to gravitation
 PROPERTIES
    nobjs = 3 & 
-   mass = [5.97e24, 1.989e30, 1.989e30]
+   /*@label "mass_values" */ mass = [5.97e24, 1.989e30, 1.989e30]
+    /*@desc "The mass of the 3 objects" */
    &
    initial_pos =   [ [0.0,0.0]    ,  [0.0,4.5e10],   [0.0,-4.5e10]  ]  &
    initial_speed = [ [0.05e04,0.0],  [3.0e04,0.0],   [-3.0e04,0.0]  ]