tater, they are controllers with no actual data/managable properties. Such a controller tells the engine of the behavior of the object (node) it is linked to, nothing more. Basically it's sort of a state flag...
There's quite a few other controllers that are the same, no data. I don't specifically know what they mean/control though - simply because well, I don't mod
. I'm sure others know...
[edit] There are other controllers that are unknown in the current S3D though. The only controllers that will remain uneditable in the next S3D are the ones that have animation (3d or speech) data...