Possible Clues:

• Punctuation marks in compound words
• Marks in compound words
• They have broken the mother-in-law
• Tic-tac-toe symbols
• Jack-in-the-box needs?
• Kin of dashes
• '-' marks
• State-of-the-art features
• *They may be at the end of the line
• Jack-in-the-box needs