Actually, none of those checkboxes appear to do anything, in a regular CoronaMaterial as well as the LightMaterial. I am not sure whether they should work, that would be for the devs to say
The way I am used to doing it is using the RaySwitch material (drop the LightMtl into the Global Illumination slot, leave the Directly visible slot empty)
It used to work but in the daily builds it’s broken.
The corona tag works but when you apply a light material to a selection tag the whole object is invisible instead of just the part you apply the light material on.