I really have no idea about this. I saw a question related to it on the Tech test once, but if memory serves, it does not answer this question. I see schools have a ham set-up, and kids (I assume) use it to transmit alongside a licensed operator. What about at home, if you want to teach your kids? Are they allowed to call CQ alongside you, with the station callsign? Or talk on-air with a contact with the op/parent doing the identifying? Not talk on air at all?