Related Clues:

• Ltr. extra
• Abbr. before a colon
• Routing letters
• In this env.
• Memo abbreviation
• Something besides the ltr.
• Mailed doc.
• Abbr. on a memo
• Abbr. on a business envelope, perhaps
• Bus.-letter letters
• Abbr. on envelopes
• Abbr. before the name of a memo recipient
• Bus. envelope abbr.
• Business envelope abbr.
• RSVP card, e.g.