While building the Expandable Color Ramp for Poser i watched several Blender videos about how the Color Ramp was/is used in Blender.  There was one video where the guy showed an extra feature of Blenders color ramp that is not listed in the Blender manual. And that is Transparency.  He took a color and expanded it to show an extra parameter that could be moved from fully opaque to transparent.  Problem being that requires an extra output and I did not feel like adding that extra code into this material.  HOWEVER, there is a way to duplicate that effect and that is to do a copy paste of the Expandable Color Ramp and then change the colors to White and shades of Gray/Black, also make sure to use the Gradient or Eased Gradient blend modes as the HSV modes probably won't work as expected.  See below for a couple of pictures showing the setup.

The Color Ramp on the Right is setup to provide Transparency into the Root Node.  Color 1 is White (opaque) and Color 2 is Black (transparent) and color 3 is White.  So you can see the output of the node goes from White to Black and back.  Notice the effect on the sphere on the Left side as most of Color 1 disappears and Color 2 slowly fades in. 

Above are two Andy's with the same material but the one on the right has the Color Ramp set to provide a transparency effect.  Which you can see as parts of the first color are fading out and Color 2 is gone or just starting to fade in.

The other benefit of not having it in the same node is that you can change where the Transparency effect will occur instead of being limited to a fixed position as in Blender.