The preset is set for skin and the values are taken from a Nvidia paper on SSS.
This saved our butt on the last project that required full frame SSS in many shots but would fall down on standard character renders as it really isn't meant for anything with an Alpha, let alone back scattering.
Apply the macro to a rendered diffuse pass and you'll get an idea of what it does
Hope someone finds it useful.
here's an image.. not the best example by any means