This is an enormously helpful link. Of course, I should expect this syntax to vary from vendor to vendor, which means it's going to be a bear to debug if I want to write a bunch of rules and get them correct for things like calling 911.

I'm already planning to set up NoMoRobo -- in general -- but forward a specific set of phone calls directly to voicemail, such as the weekly prerecorded phone spam we get from my daughter's school. We do want the message, but there's no point in ringing the phone for it.

So, yeah, from day 1 I'm going to be diving into all these rules and plans and such, and voip.ms doesn't seem to have this level of documentation at all.