Related Clues:

• Assisi trio?
• Road signs may warn of them
• Handy Scrabble tiles
• Ends of scissors?
• 'Sleepless in Seattle' quartet
• Quartet in ''sassafras''
• Letters written in distress, especially
• Wavy-line shapes
• Indicators of possessiveness
• Tricky road curves
• More than a third of "Mississippi"
• Half of ''suds''
• Letters of plurals
• Gossip center?
• Half of the letters in this answer's row