Related Clues:

• Letters on an invitation
• Key feature?
• Request of an invitee, briefly
• Applicant's offering
• Invite letters
• ''Please reply''
• Accept an invitation
• Go on with
• Say 'I'll be there'
• Reply
• "Let us know," on an invitation
• Letters for an invitee
• Invitation initials
• Request from a party leader
• Retort