Related Clues:

• Abbr. on an envelope
• Answer an invitation
• Memo abbr.
• Postal abbr.
• 'Now hear this!': Abbr.
• Abbr. that often precedes a colon
• Invitation inits.
• Address abbr.
• Business letter abbr.
• Env. notation
• Abbr. on some letter headings
• Letter abbr.
• Guests may do it
• Answer
• Letters on letters