Related Clues:

• Invitation inscription
• ''Let us know if you're coming''
• Say whether you'll come
• Friday dress, perhaps
• "We're not serving liquor," on invites
• "Please answer"
• Accept or decline
• Inform the host
• Part of a prospective bride's pile
• Party stipulation, briefly
• Say you'll go, say
• Letters on an invite
• It may involve regrets
• Letters before a phone no., perhaps
• Promise attendance, briefly