Related Clues:

• Bibliophile's label
• One-in-a-million
• Far from frequent
• Of interest to collectors, say
• Chophouse request
• Atypical
• Quite unusual
• Like a 1943 copper penny
• Out of the ordinary
• Like cabs on a rainy day, seemingly
• Facing extinction
• Answer to a waiter, sometimes
• Nearly extinct
• Still pink
• Uncommonly good