Backup required
Requesting additional police assistance.
Negative
No or denial.
Affirmative
Yes or confirmation.
ETA
Estimated Time of Arrival.
10-4
Acknowledgment (similar to “Roger” or “Message received”).
Code Black
Bomb threat or suspicious package.
Code Blue
Medical emergency or need for medical assistance.
Code Red
Emergency or dangerous situation (e.g., terrorist threat or violent crime).
ETA
Estimated Time of Arrival.
BOLO
Be on the lookout (for a person or vehicle).