Possible Clues:

• Street corner things that tell you you can't park here, if you should stop, where to go, etc
• STOP and YIELD
• Validates a contract
• Indications of gang leader stopping offences?
• The stars in a number of versions of The Omen perhaps
• Aquarius and Aries
• Harbingers
• Zodiac ingredients
• Libra and Leo
• PED XING and others