Related Clues:

• This could raise a red flag
• Utility reading
• Hack counter
• Parking space adjunct
• Electrical reading device
• Parker's concern
• It's fed at curbside
• Postage source
• Curbside payment collector
• Poetic rhythm
• Fare computer
• Rhythmic element
• 59-Across element
• It could raise a red flag
• Instrument for measuring quantity