How often must you identify with your FCC-assigned call sign when using tactical call signs such as “Race Headquarters”?

Tactical call signs, such as "Race Headquarters" or "Checkpoint 3," are incredibly useful during public service events because they identify a function or location rather than a specific operator, who might change during a shift. However, a tactical call sign does not replace your legal obligation to identify your station. You must still append your official FCC-assigned call sign according to standard rules: at the end of each communication and at least every 10 minutes during a communication.