Related Clues:

• File extensions
• Restaurant bills
• "... for __, a tooth ..."
• Soda can openers
• They make indents
• They're run at bars
• Surveillance, so to speak
• Cops may keep them on a suspect
• Many have file names
• Dinner bills
• Window components
• Bar pickups
• Keep __ on: observe
• Not bat --
• File markers