Related Clues:

• Attendance request
• Letters on a letter
• Setup provider's abbr.
• Answer, as an invitation
• Reply, briefly
• Answer, briefly
• Get back to the host or hostess
• It may consist of regrets
• Letters sometimes preceding a phone no.
• Evite.com request
• "Reply, pls."
• ''Let us know,'' on an invitation (Abbr.)
• ''Let us know,'' initially
• Confirm, in a way
• Regrets, perhaps