The category "<air_command_prefix-roger>" can be expressed as follows:

<air_command_prefix-roger>

<controller> <roger>

<roger>

<roger> <controller>

<roger> <unit_call_sign>

<roger> <unit_call_sign> <controller>

<unit_call_sign> <controller> <roger>

<unit_call_sign> <roger>

<unit_call_sign> <roger> <controller>