Related Clues:

• "Heads up!" and others
• Warns of danger
• APBs, e.g
• Cellphone reminders
• Gives a tip
• Wickedly alters warnings
• Sirens, say
• Notifications from Google
• Messages often with exclamation points
• Some mass text messages
• 'Fore!' and others
• Mobilizing messages
• "Fore!" et al
• Sirens, e.g
• Google deliveries