I just read in [Wikipedia](http://en.wikipedia.org/wiki/List_of_Nikon_compatible_lenses_with_integrated_autofocus-motor
Nikon VR/Sigma OS/Tamron VC/Tokina VCM: Optical image stabilization, also called Vibration Reduction, indicated green background, a system used to compensate for vibration and other camera movement.
And I couldn't find any reference to that "green background". What does that mean ?

