Thanks for the feedback, guys. Much appreciated. The team's frequencies are all over the net, and it'll be trivial to create a Favorite list in Sentinel when and if I get the chance to go to any races this year. I just wanted to make sure they weren't grayed out due to something dumb I'd done.
It looks like they're placeholders of sorts, for something that may be coming. I can already picture little car # icons where the Service Type icons normally appear.