Basically all you need to do is set up your “Brevity code” as it’s known. All it does is allow you to convey as much information in the littlest amount of time.
I’ll echo what selco said, and I’ll add that if you’re using it via radio, you’ll want to change your words/phrases weekly, if not on a day by day basis, just to be safe. Radio comms security can be as in depth and complex as you make it.
Canadian Patriot. Becoming self-sufficient.