We use a 5-line call in structure. Send this out on Long Range radio (so you'll need a backpack or a vehicle) and an agreed channel. We default to Channel 1.
The structure is as follows:
First identify yourself and your intended recipient
(e.g. Alpha 1-2, Zombie1)
1) Direction of approach for the aircraft not yourself
(e.g. CAS requested call in: North)
2) Target description
(e.g. BMP in the open)
3) Mark (Smoke or name of map marker) - provide smoke/marker colour or additional features
(e.g. map mark Red BMP)
4) Nearest friendly position or direction
(e.g. Friendlies south 120 metres)
The pilot will provide a readback to confirm details. You should confirm:
"Good Readback"
This is your opportunity for further remarks. For example you may want to request specific ordnance:
"Napalm requested"
Once the pilot confirms there'll be a pause while they line up and approach. They'll then confirm with their bearing:
"In 120"
If you are happy, clear the call-in:
"Cleared Hot"
And sit back and watch the destruction.