Related Clues:

• Sounds the alarm, e.g.
• These may be red
• Urgent warnings
• Gives a heads-up
• Sirens
• Cautionary signals
• Trading updates
• Cautions
• Gives a heads up
• Red lights and flares
• Foghorn blasts, e.g.
• Notifies
• Beeps, maybe
• Red ones are quite urgent
• Security concerns