Related Clues:

• Part of a prospective bride's pile
• Say you'll go, say
• Letters on an invite
• It may involve regrets
• Letters before a phone no., perhaps
• Promise attendance, briefly
• Don't just show up
• Initials on invitations
• Short answer?
• Abbr. on an invitation
• Use Evite
• Use an SASE
• Offer feedback, in a way
• Letters from the host
• Invitation abbreviation