Possible Clues:

• It's often presented during a 38 Across
• Sign of commitment in battle arena
• Employ people on time and call for a sign of commitment
• Booking band, pending future contract
• It may precede union battle with clique of antique dealers
• Valentine Day's gift, perhaps
• Indication of forthcoming match in fight arena
• Battle arena's symbol of unity
• Symbol of impending marriage
• What would-be union member might get from recruitment group