Related Clues:

• Entry requirement, at times
• Check-cashing aid
• Entrance requirement, perhaps
• Proof of who you are
• It's revealing
• Proof of membership, maybe
• A bouncer might check it
• Proof of age, maybe
• Security checkpoint item
• Entrance need, perhaps
• Proof of who you say you are
• Proof of employment, perhaps
• Bouncer's check
• Age proof
• It may be swiped