An exercise technique used successfully is that of sending the same message over multiple channels. This means that a message from State to a county EOC is transmitted via the RACES, Civil Air Patrol, SECURE, Local Government or other available and appropriate radio systems.
Following the exercise, you request that the received message forms be mailed back to you to show both accuracy and time of receipt. In county to city exercises, CB radio may be thrown into the mix.
---Stan Harter, KH6GBX